'62 Buick Lesabre trans help?

[clintas12]

New to the forum world, sorry if it takes a bit to get to any replies. 

 

Now that that's out of the way, i recently picked up a new to me buick that I'm so excited about! It's got the 401 nailhead with the factory Dynaflow and of course; the transmissions no good! (I can only assume. The pans got a hole in it, and the kid i picked it up from had said he drove it. He also said a handful of other things that didn't turn out to be the case, but nature of the beast) 

Anyways, after a fair bit of research I have found that an ST400 may be the easiest route to go and lucky me.. I found one 4 hours away! I imagine it needs rebuilt, but who cares?! 

I know it isn't exactly plug and play, and I'm sure I'll have a hell of a time trying to find any brackets or anything else I'm going to need (surely) but it's going to be the easiest option, right? I'll attach photos of the transmission, should be exactly what I'm looking for I believe. Just would like some confirmation lol I'm really hoping NTX5467 ends up seeing this, I've seen his replies on a few other posts and he sure seems to be the right one to ask about this!

Also, it runs beautifully for anyone curious!

 

[joe_padavano]

Nice find! Yes, that bolts to your 401, and it's a 1965 model trans, so it doesn't have the one-year-only "features" of the 1964 models. Nomenclature aside, it's pretty much a switch-pitch TH400, so parts mostly grow on trees. The two prong electrical connector is for the switch pitch and kickdown solenoids. The prongs are in a "T" shape. The crossbar of the "T" is the switch pitch wire, the upright leg is the kickdown wire. Obviously you'll need to rig switches. The other big problem is the shift pattern. This 1965 trans uses the common P-R-N-D-S-L pattern.

[drhach]

I've done that conversion on the exact same car. I'll be happy to answer any questions. It wasn't terribly complicated. I will say your quickest path to getting the car running is to rebuild the Dynaflow. I don't want to talk you out of the conversion if that's what you really want. But I will be honest that if I had it to do over again, I would have just stuck with the Dynaflow. It was fun to do the conversion and it was a good project, I learned a lot. But the net gain was not that significant. 

 

Regards,

Dan 

[Steve Braverman]

I had a 63 LeSabre with the same trans. I found it to be very enjoyable to drive. Super smooth with no shifting, but not sluggish either. Acceleration from 50-90 was impressive. I would fix the original trans or find a correct replacement.

[clintas12]

20 hours ago, joe_padavano said:

Nice find! Yes, that bolts to your 401, and it's a 1965 model trans, so it doesn't have the one-year-only "features" of the 1964 models. Nomenclature aside, it's pretty much a switch-pitch TH400, so parts mostly grow on trees. The two prong electrical connector is for the switch pitch and kickdown solenoids. The prongs are in a "T" shape. The crossbar of the "T" is the switch pitch wire, the upright leg is the kickdown wire. Obviously you'll need to rig switches. The other big problem is the shift pattern. This 1965 trans uses the common P-R-N-D-S-L pattern.

Thanks! I was really nervous I'd have trouble getting everything together for the rebuild. 

[clintas12]

7 hours ago, drhach said:

I've done that conversion on the exact same car. I'll be happy to answer any questions. It wasn't terribly complicated. I will say your quickest path to getting the car running is to rebuild the Dynaflow. I don't want to talk you out of the conversion if that's what you really want. But I will be honest that if I had it to do over again, I would have just stuck with the Dynaflow. It was fun to do the conversion and it was a good project, I learned a lot. But the net gain was not that significant. 

 

Regards,

Dan 

The trans for all I know may be good, the pans got a sizeable hole in though and really like the idea of having overdrive and hearing/feeling it shift, plus the gas mileage goes way up from what I've read. I do definitely intend on getting the DF checked out and making sure it's good for when (if) I go to sell the car though, but in no hurry for that. 

So you've done this swap before? From what I've collected (please correct me if I'm wrong) I need to get the starter, linkages, and I believe a flex plate? Also I imagine the driveshaft will need to go to the machine shop to get relengthened. And the flex plate needs to go as well, something about a center bore or something? 

I apologize in advance, I by no means am a mechanic, just handy enough I like to think. 

[drhach]

I would say my fuel economy went from terrible to just pretty bad. Although I did add dual quads. So maybe I'm not the guy to ask about that. 

 

You can reuse the starter. You dont have to machine the crank. But you do need to get a spacer/ adapter. Centerville auto sells them. You do also need the flex plate. For that trans.

 

You'll need to shorten the drive shaft and source a new yoke. Also you you'll need to work out a new trans mount and shift linkage. 

 

I modified my existing trans crossmember and used a generic shift linkage from Ebay.

 

The current trans kickdown is mechanical. The 400 is electric. You can use a Buick st400 kickdown from a 65 or 66. They will have the circuit for the torque converter. 

 

I would also get that torque converter rebuilt. I have a nice used one if you're interested.

 

I modified a shift quadrant from a 66 riviera for the new shift pattern

 

 

Edited February 3, 2023 by drhach (see edit history)

[clintas12]

43 minutes ago, drhach said:

I would say my fuel economy went from terrible to just pretty bad. Although I did add dual quads. So maybe I'm not the guy to ask about that. 

 

You can reuse the starter. You dont have to machine the crank. But you do need to get a spacer/ adapter. Centerville auto sells them. You do also need the flex plate. For that trans.

 

You'll need to shorten the drive shaft and source a new yoke. Also you you'll need to work out a new trans mount and shift linkage. 

 

I modified my existing trans crossmember and used a generic shift linkage from Ebay.

 

The current trans kickdown is mechanical. The 400 is electric. You can use a Buick st400 kickdown from a 65 or 66. They will have the circuit for the torque converter. 

 

I would also get that torque converter rebuilt. I have a nice used one if you're interested.

 

I modified a shift quadrant from a 66 riviera for the new shift pattern

 

 

Let's start with the flexplate, that is no problem I don't seem to have any trouble at all finding anything there. The spacer/adapter you were talking about, I'm guessing that is for the crank? (Once again, I'm not a mechanic so bare with me please. More dumb questions are to follow I assure you lol)

The yoke.. how would I go about finding that? I don't imagine I could just swap the one from the dynaflow onto the ST can I? 

I saw that the guy I'm buying the transmission from has the kickdown so I'll make sure to get that along with the trans when I pick it up this weekend.

 

I'd be happy to buy that from ya a little down the road if there's anyway to private message we can swap emails to get back in touch? Idk if there's any notifications, messages, or anything of the sort on here. I've just been reloading the tab. 

And finally, that looks beautiful! I was curious what orientation the switches were! I'll have to keep an eye out for the shift pattern aswell, i'd like to have the transition look and feel as natural as possible. Mine looks pretty rough inside and out, but if I can get it moving then I can start on making it pretty. Never gonna achieve what you've got though I'm sure lol

[clintas12]

1 minute ago, clintas12 said:

Let's start with the flexplate, that is no problem I don't seem to have any trouble at all finding anything there. The spacer/adapter you were talking about, I'm guessing that is for the crank? (Once again, I'm not a mechanic so bare with me please. More dumb questions are to follow I assure you lol)

The yoke.. how would I go about finding that? I don't imagine I could just swap the one from the dynaflow onto the ST can I? 

I saw that the guy I'm buying the transmission from has the kickdown so I'll make sure to get that along with the trans when I pick it up this weekend.

 

I'd be happy to buy that from ya a little down the road if there's anyway to private message we can swap emails to get back in touch? Idk if there's any notifications, messages, or anything of the sort on here. I've just been reloading the tab. 

And finally, that looks beautiful! I was curious what orientation the switches were! I'll have to keep an eye out for the shift pattern aswell, i'd like to have the transition look and feel as natural as possible. Mine looks pretty rough inside and out, but if I can get it moving then I can start on making it pretty. Never gonna achieve what you've got though I'm sure lol

 

58 minutes ago, drhach said:

I would say my fuel economy went from terrible to just pretty bad. Although I did add dual quads. So maybe I'm not the guy to ask about that. 

 

You can reuse the starter. You dont have to machine the crank. But you do need to get a spacer/ adapter. Centerville auto sells them. You do also need the flex plate. For that trans.

 

You'll need to shorten the drive shaft and source a new yoke. Also you you'll need to work out a new trans mount and shift linkage. 

 

I modified my existing trans crossmember and used a generic shift linkage from Ebay.

 

The current trans kickdown is mechanical. The 400 is electric. You can use a Buick st400 kickdown from a 65 or 66. They will have the circuit for the torque converter. 

 

I would also get that torque converter rebuilt. I have a nice used one if you're interested.

 

I modified a shift quadrant from a 66 riviera for the new shift pattern

 

 

Also.. the kickdown, I'd be looking for the kickdown switch, a linkage, and a bracket that mounts to the intake manifold? I'm just going based off of what I'm seeing in and ebay search for "65 st400"

[joe_padavano]

13 hours ago, drhach said:

I would say my fuel economy went from terrible to just pretty bad. Although I did add dual quads. So maybe I'm not the guy to ask about that.

Both transmissions have a 1:1 top gear ratio, so unless one is driving around in the lower gears a LOT, or the old trans was massively slipping, there is no difference in mileage.

[drhach]

Here's the adapter I was telling you about. 

 

57 to 63 pilot/ converter adaptor | Centerville Auto Rep (nailheadbuick.com)

 

It looks like he also has (used) flex-plates for sale. 

 

I wanted to use the Buick kickdown just because it looks OEM. I'm sure there are a hundred other ways to go. I felt that the less I had to reinvent the wheel the better. 

 

If you have the yoke from the transmission that you're buying, you can use that one. If you can't get that, make sure you measure the of the bushing. Mine (1965) had a smaller diameter and less common yoke. I ended up changing the tailshaft housing to accept the more common bigger diameter unit. It just made finding parts easier. The seal and the bushing for the smaller diameter yoke are not terribly common. 

 

 

Here's a link to the thread about my car. I think I have some pictures and discussion there. Feel free to PM me. I can discuss it more or I can send you my phone number and we can talk. 

 

Not to be a broken record, but you still may want to try to get the Dynaflow working. It's probably your quickest and easiest path to driving the car. 

 

 

 

 

 

[drhach]

26 minutes ago, joe_padavano said:

Both transmissions have a 1:1 top gear ratio, so unless one is driving around in the lower gears a LOT, or the old trans was massively slipping, there is no difference in mileage.

Thsat isn't necessarily true. There are frictional losses that occur. It takes horsepower to run these things. 

[joe_padavano]

13 minutes ago, drhach said:

Thsat isn't necessarily true. There are frictional losses that occur. It takes horsepower to run these things. 

There is some slippage in the converter. That is a second order effect and won't make a noticeable difference in mileage between the two.

[drhach]

That's part of it. There also are shear forces all through the system, not just the TC. These forces are inherent in a hydraulic system and they are additive. They can be more or less present based on design. The design of the Dynaflow consumes more horsepower than the design of the TH400. It's not just the torque converter. It's the whole package. 

 

 

Here are some common horsepower requirements for different GM transmissions. All are 1:1 at top gear. But you are going to use different amounts of power to sustain that speed. I doubt anyone has ever measured a Dynaflow just because it has never really been considered a viable transmission for performance work. 

 

 

GM
PG 18 hp
TH-350 36 hp
TH-400 44 hp

[joe_padavano]

2 hours ago, drhach said:

That's part of it. There also are shear forces all through the system, not just the TC. These forces are inherent in a hydraulic system and they are additive. They can be more or less present based on design. The design of the Dynaflow consumes more horsepower than the design of the TH400. It's not just the torque converter. It's the whole package. 

 

 

Here are some common horsepower requirements for different GM transmissions. All are 1:1 at top gear. But you are going to use different amounts of power to sustain that speed. I doubt anyone has ever measured a Dynaflow just because it has never really been considered a viable transmission for performance work. 

 

 

GM
PG 18 hp
TH-350 36 hp
TH-400 44 hp

That is certainly correct, but these published numbers apply primarily to drag race applications where the internal friction and HP loss is usually measured at something like 5000-6000 RPM. Frequently these racing transmissions have internal mods with boosted line pressures as well. People loose a lot of sleep over the 8 hp difference between TH350 and TH400 - on the street that difference is meaningless. I have no idea of the internal friction in the Dynaflow. I suspect that at freeway speeds, that's in the noise compared to aero drag, rolling resistance, and other effects. But as we all know, after putting all the time and money into a major mod like this, the "butt dyno" always says that there's an improvement.

[JACK M]

So, if going to all that trouble would not a 700r4 be a better choice?

[drhach]

All good points. As I said earlier, if I had it to do all over again, I probably wouldn't have bothered. So my "butt dyno" didn't register huge numbers

 

I think R4 has OD which I agree would ultimately be a better choice. But still, I probably would just fix the Dynaflow. The car is what it is. If the OP really really wants to do the change, that's the final decision point. 

[joe_padavano]

53 minutes ago, JACK M said:

So, if going to all that trouble would not a 700r4 be a better choice?

The 700R4 and 200-4R, while OD transmissions, are not the strongest. Either one requires internal modifications to survive behind a big block.

[Frank DuVal]

20 hours ago, clintas12 said:

idea of having overdrive and hearing/feeling it shift,

Um, the ST400 does not have overdrive. As said above, the ST400 and the Dynaflow are 1:1 at speed. 
 

I like not feeling a shift, because it is different. 😉  

[drhach]

I think the "not feeling it shift" thing was actually a selling point. Buick owners didn't want harshness. These aren't Chevys. 

[pfloro]

2 hours ago, drhach said:

I think the "not feeling it shift" thing was actually a selling point. Buick owners didn't want harshness. These aren't Chevys. 

Maybe it was a Buick marketing phrase or perhaps I heard it on the street: 

 

"The car that shifts a thousand ways!" 

 

There is nothing like that continuous flow of Buick power...

 

Paul

 

 

Edited February 3, 2023 by pfloro (see edit history)

[JACK M]

20 hours ago, joe_padavano said:

The 700R4 and 200-4R, while OD transmissions, are not the strongest. Either one requires internal modifications to survive behind a big block.

I am not much of a GM guy, but I see alot of the OD trannys behind the obligatory Bowties.

[61polara]

In addition to the Dynaflow being a very smooth transmission with no shifting, it is a very quiet transmission which makes for a very quiet ride.  Possibly the quietest of the time.

[joe_padavano]

56 minutes ago, JACK M said:

I am not much of a GM guy, but I see alot of the OD trannys behind the obligatory Bowties.

Your point? They came from the factory behind smogger 305s that were hard-pressed to make the rated 160 HP. There's a reason why GM rapidly moved from the 4L60E (computer-controlled 700R4) to the 4L65E to the 4L70E, each time upgrading the internal hard parts. The fact that people bolt then into older cars doesn't mean they survive.

[JACK M]

I was only pointing out that they seem to be popular.

I would not know the differences among these that you mentioned but know of several GM automatic ODs that are driven often in street rods.

So they must at least be functional.

I guess to answer the question, the point is that I see these in 90% of all homebuilt contraptions, usually small block and doesn't matter if its a Ford (mostly Fords) or Mopars, or whatever that hot rod originated as. Most of them get SBCs and 700R4s.

My preferences in those genres would be Ford in a Ford, GM in a GM and so on, but this is just me.

I suspect that a major percentage of AACA members don't look down their noses at hot rods, but those that do are quite vocal about it.

Fun stuff for sure,

[joe_padavano]

24 minutes ago, JACK M said:

I was only pointing out that they seem to be popular.

I understand, but so are LS swaps and I wouldn't recommend that either. 😉

 

Seriously, most people who modify their cars are lemmings who do what the cable shows and ZooTube videos tell them they "must" do. You MUST make radical changes to your car to make it "reliable", without any real thought or engineering or even skill. Frankly, many if not most of the aftermarket vendors aren't that knowledgeable either. Don't get me started on the mis-information about disc brake swaps. I don't know how many threads I've read from people who "upgraded" their brakes and now are complaining that the car stops worse than it did before.

 

Edited February 5, 2023 by joe_padavano (see edit history)

[rocketraider]

A Buick owner who replaces a Dynaflow with a 700 is going to think someone saddled him with a real HydraMatic- one of those fluid coupling four-speed jobs that Buick said was jerky and not suitable for Buicks. Yet it was fine for Cadillacs, Lincolns and Rolls-Royce- all of whom had long left torque tube drivelines behind.

 

You have the Nailhead pattern 400, so if you elect to change from Dynaflow that will be your best option. It will give you TurboHydraMatic efficiency and be a much simpler swap than trying to put either a 700 or 2004R into the 1962 Buick chassis. And as Joe P has pointed out, being a 1965 transmission it has the refinements the 1964 1st year transmission lacked. Notably a true selectable intermediate range (S or L2) like earlier HydraMatics had, instead of only D and L ranges as in 1964.

 

I've often wondered if that's how they got Pontiac and especially Oldsmobile to buy into THM. They'd had Super range on HydraMatic since 1952 or so, and Cadillac owners were used to being able to select a DRIVE position that would keep HydraMatic in 3d gear if needed.

[Frank DuVal]

On 2/4/2023 at 12:59 PM, joe_padavano said:

There's a reason why GM rapidly moved from the 4L60E (computer-controlled 700R4) to the 4L65E to the 4L70E, each time upgrading the internal hard parts.

Rapidly is not the word I would use to describe installing a transmission for 21 model years...  But, as engine horsepower increased, and trucks got heavier,  they did install the higher torque models (the 60, 65 and 70 are the relative torque ratings) in the large trucks (standard trucks as I call them 😁).

 

The 4L60E is fine after the first rebuild!  😉   Millions still on the road. People are rebuilding the 4L60E with upgraded guts and putting them behind all sorts of street rods. Of course there is hardly any difference in outside appearance in the 4L60E, 4L65E and the 4L70E. The 4L80E is a larger case with more bolts on pan and bellhousing.

[joe_padavano]

1 hour ago, Frank DuVal said:

Rapidly is not the word I would use to describe installing a transmission for 21 model years...  But, as engine horsepower increased, and trucks got heavier,  they did install the higher torque models (the 60, 65 and 70 are the relative torque ratings) in the large trucks (standard trucks as I call them 😁).

 

The 4L60E is fine after the first rebuild!  😉   Millions still on the road. People are rebuilding the 4L60E with upgraded guts and putting them behind all sorts of street rods. Of course there is hardly any difference in outside appearance in the 4L60E, 4L65E and the 4L70E. The 4L80E is a larger case with more bolts on pan and bellhousing.

The 4L80E is essentially a TH400 with an overdrive gear set stuck between the front pump and the rest of the trans. Most TH400 hard parts for gears 1-3 interchange with those in the 4L80E. Gear ratios for 1-3 are the same between the two  (2.48:1 first, 1.48:1 second, and 1:1 third).

 

 

[PONTIAC1953]

On 2/2/2023 at 9:39 AM, drhach said:

I've done that conversion on the exact same car. I'll be happy to answer any questions. It wasn't terribly complicated. I will say your quickest path to getting the car running is to rebuild the Dynaflow. I don't want to talk you out of the conversion if that's what you really want. But I will be honest that if I had it to do over again, I would have just stuck with the Dynaflow. It was fun to do the conversion and it was a good project, I learned a lot. But the net gain was not that significant. 

 

Regards,

Dan 

Really ?, I have owned and driven both the 1958 Roadmaster with the Dynaflow, and the 1965 Riviera with the Switch Pitch 400 trans, the different in performance is like Night & Day, I also built a 1967 Wildcat SP400 trans, mated it to a 1970 Bonneville 455 V8, installed them into my 1962 Grand Prix (Good Bye Slim Jim Junk), giving the Roadmaster some throttle and you'll start moving ok, give the Riviera or the Grand Prix some throttle, and you'll be holding/hanging on to the steering wheel.

[PONTIAC1953]

21 hours ago, rocketraider said:

A Buick owner who replaces a Dynaflow with a 700 is going to think someone saddled him with a real HydraMatic- one of those fluid coupling four-speed jobs that Buick said was jerky and not suitable for Buicks. Yet it was fine for Cadillacs, Lincolns and Rolls-Royce- all of whom had long left torque tube drivelines behind.

 

You have the Nailhead pattern 400, so if you elect to change from Dynaflow that will be your best option. It will give you TurboHydraMatic efficiency and be a much simpler swap than trying to put either a 700 or 2004R into the 1962 Buick chassis. And as Joe P has pointed out, being a 1965 transmission it has the refinements the 1964 1st year transmission lacked. Notably a true selectable intermediate range (S or L2) like earlier HydraMatics had, instead of only D and L ranges as in 1964.

 

I've often wondered if that's how they got Pontiac and especially Oldsmobile to buy into THM. They'd had Super range on HydraMatic since 1952 or so, and Cadillac owners were used to being able to select a DRIVE position that would keep HydraMatic in 3d gear if needed.

the Dual Range Hydra-Matic Drive trans from 1952 to 1956 does upshifts 1-2,2-3 and holds back the 3-4 upshift until 70 mph in Drive right position (Super or S in Oldsmobile) and if you slow down below 70 mph the downshift to 3rd will occur.

[PONTIAC1953]

On 2/3/2023 at 9:06 AM, drhach said:

Thsat isn't necessarily true. There are frictional losses that occur. It takes horsepower to run these things. 

very true drhach, when the 1956 Pontiac engine was increase to 316, and the Controlled Coupling Hydramatic became available, a engineer/teacher at a engineering school my friend Ivan attended said "the 316 V8 makes 20 more horsepower than the 287, and the Strato-Flight Hydramatic trans (controlled coupling) takes 20 more horsepower to operate than the Single Coupling Dual Range does"

[drhach]

1 hour ago, PONTIAC1953 said:

Really ?, I have owned and driven both the 1958 Roadmaster with the Dynaflow, and the 1965 Riviera with the Switch Pitch 400 trans, the different in performance is like Night & Day, I also built a 1967 Wildcat SP400 trans, mated it to a 1970 Bonneville 455 V8, installed them into my 1962 Grand Prix (Good Bye Slim Jim Junk), giving the Roadmaster some throttle and you'll start moving ok, give the Riviera or the Grand Prix some throttle, and you'll be holding/hanging on to the steering wheel.

A 1958 Roadmaster versus a 1965 Riviera? I don't think transmission had much to do with the Riv being faster  The Riviera is probably 500 pounds lighter.

 

[PONTIAC1953]

2 hours ago, drhach said:

A 1958 Roadmaster versus a 1965 Riviera? I don't think transmission had much to do with the Riv being faster  The Riviera is probably 500 pounds lighter.

 

only 350 lbs lighter, not that much at all

[clintas12]

Apologies for the delay in update, but I wound up patching the pan. Put it back on and filled up, and it's actually moving! I figure at this point, I'll just try and save the original trans since it's already turned out better than I had expected / hoped for. The big issue I'm having now is trying to get it to go into reverse and it's leaking fluid from the bell housing. I assume it's the seal, but haven't had anymore time to mess with it. 

[Rusty_OToole]

I was told by an old transmission guy that if the front seal is leaking might as well plan on a full rebuild, it is never just the seal but the pump is worn and so is the rest of the trans.

 

In your case the seal may have failed because it ran dry of oil but still. If you have to take the trans out to get at it might as well go thru the trans.

[Sonomatic]

I'm going to add my two cents, and, regrettably contradict Rust_OToole's advice.  Jim Hughes of Perryville, Ohio gave me just the opposite advice.  I have a '50 Buick Special with a late '51-'52 Dynaflow which is/was leaking from the front pump seal.  His advice to me was to replace the seal and try it, because, in his experience, the front bearing being right next to the pump, it is the most oiled bearing in the transmission and rarely needs replacement.  That is exactly what I'm in the process of doing now.  I will be able to speak from personal experience in a week or two. It has been stated that the pan has a hole in it.  My first question is, is it a gash, or did something poke through it and possibly damage the valve body?  If the pan has a gash in it, bull it off, straighten it out, weld it up and try it.  I think I would try it even if the front seal is leaking.  If you go to the Technical forums and look up 1950 Buick Dynaflow leak, you will see a video of how much my transmission was leaking.  I was driving it that way, not far, a couple of miles, but, even with a leak that large, you can see if the transmission works, then you know something.  As far as the ST400, grab it, it's money in the bank whether you use it or not.  But my advise is to get the car running and driving, see what you've got, then start making modifications.  One other thing about the Dynaflow, in 1955 an update was made where the Dynaflow had a mechanical/hydraulic type of switch pitch in the torque converter.  As drhach has stated, the difference between his Dynaflow and his ST400 wasn't that much in his application.  When I first got my '50 Special, I read all the negative comments about the Dynaflow, it's slow, inefficient, and on and on.  I was investigating changing to a manual or maybe a modern automatic.  After driving it for real, in real traffic, I think it's fabulous, and I'll be keeping mine.  If you check my other post in Post War for my Dynaflow saga, you'll see that I'm taking the time to collect up tools to do one of these transmissions again.  Right now, I'm looking for another late '51-52 to do a complete rebuild on so I can see what's involved and maybe help someone else. There was also some talk on here as to the 700r4 being weak and not holding up.  All I can say is, the 200R4, the baby sister to the 700R4, is what's installed behind the turbo V6 in the Grand Nationals, and I myself would think twice about pairing off with one of those in any V8 Buick ever made.  If you need your 200R4 to be a little more durable, I know first hand that Art Carr made a lot of modified parts to take car of the weaknesses in the 200R4.  One more thing, I have collected a stack of information about Dynaflows, and one of the things I ran across in one of the service manuals was how to modify a wooden file handle so that you could stick it on one of the converter bolts while the trans is on the bench and check pressures by hand cranking it.  The manual said if you can supply a constant 60 rpm, that's enohgh to develop the 90 psi to check the transmission on the bench.  I say, get that Dynaflow to hold oil and see what you've got.  If you thy it and don't like it, PM me, I might have to come get it.  Most of all, enjoy your Buick!     @herbertsaylor8912