TheRev Posted August 29, 2014 Share Posted August 29, 2014 Need some help here. I have located a 1965 ST 400 out of a wildcat. Notwithstanding shift indicator issues, will this trans fit my car? I know the bell housing will fit my nailhead, more concerned about cross member issues and short/long shaft. Dynaflow is limping along after 52 years and 136k miles. While on topic, I can also pick up a switch pitch 400 but I have no intentions of racing this car. Should I go with a switch pitch assuming the 400 will bolt in? Both of these transmissions will need to be rebuilt. Thanks Link to comment Share on other sites More sharing options...
60FlatTop Posted August 29, 2014 Share Posted August 29, 2014 If you are 30ish go for the swap. If you are an old guy rebuild your Dynaflow, it won't have as many surprises.I have a good used '62 Dynaflow down in the cellar. At least it was when I put it there around 1986.Bernie Link to comment Share on other sites More sharing options...
Lapham3 Posted August 30, 2014 Share Posted August 30, 2014 Go to V8Buick.com and do a search=this swap has been done by quite a few-good luck Link to comment Share on other sites More sharing options...
RivNut Posted August 30, 2014 Share Posted August 30, 2014 You need to machine the hole in '65's flex plate to fit the larger '62 crank hub. You'll need the starter for the '65, and to make everything work, you'll need the carburetor and all of the linkage - mechanical and electric. You don't say if the swap would be in a column shift or console (floor) shift. I don't know about drive shaft lengths for the '65. Link to comment Share on other sites More sharing options...
old-tank Posted August 30, 2014 Share Posted August 30, 2014 I you are going go to that much trouble adapt it to a more modern overdrive transmission: http://www.transmissionadapters.com/Those later dynaflows were actually really good transmissions if fresh and functioning as designed. And yours is a known quantity and a good candidate for rebuild...the others may not be ( things like a cracked case may not show up until installation ) Link to comment Share on other sites More sharing options...
TheRev Posted September 2, 2014 Author Share Posted September 2, 2014 I you are going go to that much trouble adapt it to a more modern overdrive transmission: http://www.transmissionadapters.com/Those later dynaflows were actually really good transmissions if fresh and functioning as designed. And yours is a known quantity and a good candidate for rebuild...the others may not be ( things like a cracked case may not show up until installation )All - thanks for the input, it is much appreciated. The cat will eventually be sporting dual quads so a trans upgrade seems worthwhile now given the dynaflow is tired. Aside from all that has been mentioned so far, does anyone know if these 65-67 400's will bolt in? I am worried about cross member issues and the like. RivNut - btw this is a console shift. Link to comment Share on other sites More sharing options...
Lapham3 Posted September 2, 2014 Share Posted September 2, 2014 As said-go to V8Buick and read. Cameoinvicta is one who has done this with a '62 Invicta=esentially the same car-good luck Link to comment Share on other sites More sharing options...
buick5563 Posted September 3, 2014 Share Posted September 3, 2014 Another guy you need to contact is Russ Martin:www.nailheadbuick.com Link to comment Share on other sites More sharing options...
NTX5467 Posted September 4, 2014 Share Posted September 4, 2014 Greg Ducato at Phoenix Trans in Weatherford, TX did a THM400 upgrade on one of our chapter members' '62 LeSabre. No carb swap, either. It made a world of difference, enough so that his then-teenaged son wanted to drive it. Seems like '65 was the magic year for a 401 and THM400 factory combination as parts donor vehicle?One thing not possibly considered is the detent plate in the steering column, for the column shifter's detents. There are also detents in the trans itself, but also a matching set in the column or floor shifter.Many people in the Riv section of things like the later THM200R-4 OD automatic in their cars to replace the DynaFlows. Many threads about that in the Riv Forum. The THM200 family takes less horsepower to run and is the new "darling" of the street rod crowd, capable of handling big-block modified V-8 power with the proper internal upgrades. You'll need about a 3.42 rear axle ratio so the OD will work at "normal road cruise speeds", though.Just some thoughts,NTX5467 Link to comment Share on other sites More sharing options...
TheRev Posted September 5, 2014 Author Share Posted September 5, 2014 As said-go to V8Buick and read. Cameoinvicta is one who has done this with a '62 Invicta=esentially the same car-good luckGot it. Thanks. Link to comment Share on other sites More sharing options...
TheRev Posted September 5, 2014 Author Share Posted September 5, 2014 This is all very helpful and much appreciated. I will keep you all posted as I work through this process. One last question, any thoughts on whether i should go with a switch pitch or just a standard 400 (assuming I stick with an era correct Buick trans)? In a car this size is the difference worth it? Link to comment Share on other sites More sharing options...
TheRev Posted September 5, 2014 Author Share Posted September 5, 2014 Greg Ducato at Phoenix Trans in Weatherford, TX did a THM400 upgrade on one of our chapter members' '62 LeSabre. No carb swap, either. It made a world of difference, enough so that his then-teenaged son wanted to drive it. Seems like '65 was the magic year for a 401 and THM400 factory combination as parts donor vehicle?One thing not possibly considered is the detent plate in the steering column, for the column shifter's detents. There are also detents in the trans itself, but also a matching set in the column or floor shifter.Many people in the Riv section of things like the later THM200R-4 OD automatic in their cars to replace the DynaFlows. Many threads about that in the Riv Forum. The THM200 family takes less horsepower to run and is the new "darling" of the street rod crowd, capable of handling big-block modified V-8 power with the proper internal upgrades. You'll need about a 3.42 rear axle ratio so the OD will work at "normal road cruise speeds", though.Just some thoughts,NTX5467Will definitely look into the THM200R, this car (as other wildcats this year) has 3.42's so we are solid there. Thanks NTX. Link to comment Share on other sites More sharing options...
John Posted September 5, 2014 Share Posted September 5, 2014 This is all very helpful and much appreciated. I will keep you all posted as I work through this process. One last question, any thoughts on whether i should go with a switch pitch or just a standard 400 (assuming I stick with an era correct Buick trans)? In a car this size is the difference worth it?You have 3 years trannies to choose from: 64 without switch pitch; 65 and 66 with switch pitch. 67 and later have a different bell housing and won't bolt up to your engine. 64 has some internal differences unique to that year and is generally viewed as less desirable; that aside, I think most of us would agree the switch pitch feature is "worth it". Link to comment Share on other sites More sharing options...
NTX5467 Posted September 5, 2014 Share Posted September 5, 2014 The Switch-Pitch has its advantages in a little more torque multiplication from a stop. I think the torque converter ratio is 2.6/1.8? The 2.6 makes the stall speed higher for less "idle creep" and more torque multiplication to get things moving. Then the 1.8 is "tighter" for less converter "slip" at cruise. A normal torque converter is about 2.0-2.2, for comparison.Buick was the only division to have Switch-Pitch, as kind of a tie-in to the multi-element torque converters of the DynaFlows, I suspect. When they discontinued its use for the 1968 model year, the sales lit mentioned "cooler operating temps" for the trans as a benefit of the fixed-stator converter. Although the Buicks used several switches on the carb (in addition to the electric kickdown switch for the THM400), some just toggle-switched the converter, but had to remember to take it out of "high-stall" for normal driving. In more modern times, you could use a vacuum switch for the lockup torque converter on (say) a 1985 Chevy pickup to possibly achieve the same thing as the various switches did in prior times.When manifold vacuum drops below a particular level, the torque converter unlocks, then re-locks when manifold vacuum returns. Generally, it takes a switch-pitch torque converter and matching front pump to change things out, plus the additional switches and wiring.At this point in time, it might be best to use a normal converter and about a 1800rpm stall speed. Parts would be more-readily available, I suspect.Just some thoughts,NTX5467 Link to comment Share on other sites More sharing options...
d2_willys Posted September 5, 2014 Share Posted September 5, 2014 The Switch-Pitch has its advantages in a little more torque multiplication from a stop. I think the torque converter ratio is 2.6/1.8? The 2.6 makes the stall speed higher for less "idle creep" and more torque multiplication to get things moving. Then the 1.8 is "tighter" for less converter "slip" at cruise. A normal torque converter is about 2.0-2.2, for comparison.Buick was the only division to have Switch-Pitch, as kind of a tie-in to the multi-element torque converters of the DynaFlows, I suspect. When they discontinued its use for the 1968 model year, the sales lit mentioned "cooler operating temps" for the trans as a benefit of the fixed-stator converter. Although the Buicks used several switches on the carb (in addition to the electric kickdown switch for the THM400), some just toggle-switched the converter, but had to remember to take it out of "high-stall" for normal driving. In more modern times, you could use a vacuum switch for the lockup torque converter on (say) a 1985 Chevy pickup to possibly achieve the same thing as the various switches did in prior times.When manifold vacuum drops below a particular level, the torque converter unlocks, then re-locks when manifold vacuum returns. Generally, it takes a switch-pitch torque converter and matching front pump to change things out, plus the additional switches and wiring.At this point in time, it might be best to use a normal converter and about a 1800rpm stall speed. Parts would be more-readily available, I suspect.Just some thoughts,NTX5467 Oldsmobile and Cadillac used the switch pitch feature from 65-67 too. Pontiac and Chevy never used the switch pitch 400 transmissions. Link to comment Share on other sites More sharing options...
TheRev Posted September 10, 2014 Author Share Posted September 10, 2014 Thanks again everyone, this was exactly the information I was looking for. Link to comment Share on other sites More sharing options...
Recommended Posts
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now