700r4 in a 70 Buick

[Romy]

I want to put a 700r4 into my 70 LeSabre 455, but I don't know how to go about it. If anyone has done this before, please help!<P>Thanks,<BR>Romy

[Guest]

Its been awhile, but here goes. I think there is a difference in the bolt pattern of Buick & Chevy 700s so you need a Buick unit. It is really pretty much a bolt in job but you will need to have the unit modified at a tranny shop for internal lockup. Shorten driveshaft, modify shift linkage, that is about it.

[The Old Guy]

The 200-4R will bolt up to your Buick and the 700-R4 will need an adapter. I have a 200 in my 73 GS and it is great!

[Romy]

I thought of putting in a 200, but the 455 is going to be putting out a lot of torque, and I was told that the 700 will be able to handle it a lot better.

[The Old Guy]

My GS runs 13,0s so it is fairly healthy,snd I have not hurt the 200 in two yrs. I run it at the track occasionaly also. It is a 4,000 Lb. convert with a 3.31 rear axle

[Buick Doctor]

The 2004R is the better choice when properly built up. No one else here mentioned the fact that the 2004R will allow full throttle upshifts into overdrive. The 700R4 will not allow full throttle into overdrive, at less than 3/4 throttle it will automatically downshift back to 3rd(drive). I know that the Grand National and GNX used the 2004R and look at the punishment those trannys take. Adapter plates and shortened driveshafts add to the expense of adding overdrive.

[rocketraider]

Back in the mid 80s when GM was eating a lot of 200s and early 700s, HydraMatic Division whined that they weren't able to build an automatic transmission that could stand up to the TurboBuick.<P>It was pointed out that HMD had built transmissions for years that could stand up to the most brutal big-blocks GM made. Why, therefore, could they not build one for a TurboBuick?<P>What they were trying to say was that the bean counters wouldn't let them spend the money to build a proper transmission for the car. Around 1986, those transmissions suddenly started getting a lot more reliable.<P>There's a thread on the Olds DF addressing the best 200s to use for a swap such as you're considering. High Performance Pontiac did a series on swapping a 200-4R into a GTO and turns out the 200 and 400 are the same length, meaning no driveshaft shortening. You might have to change the slip yoke to get the right splines, and you'd need the TVS cable and bracket to mount it to the Q-Jet. Plenty of dead 307 OD cars in junkyards to get them from.<P>Can you imagine? a big early 70s GM yacht that can get 20+ mpg and still bake the tires?

[Guest]

yeah, from what i understand the 200 was introduced about 1985 and was very weak.

[rocketraider]

Actually 1981. I had a Pontiac Safari wagon that was a 307 OD car. Couldn't pull a wet noodle out of a cat's behind and worked it to death going up long grades, but the thing got consistent 22-25 mpg until they started using reformulated gas around here. It met an untimely end at the hands of a Mitsubishi Eclipse that ran a red light and hit it square in the RR wheel. And do you know that girl drove that POS Mitsubishi away? I had a bent axle and had to be towed.<P>One thing I remember about that tranny is that it would invariably try to shift into OD any time you were in a bind and needed a quick part throttle downshift.

[Romy]

What about a 4L80E tranny? Which, out of that one, the 200 and the 700 would be the best to use. Mind you that the 455 has a around 600 lbs of torque. Are there any other tranny's that would be good for what I need? Thanks

[rocketraider]

I don't think the 4L80E will work without a computer. It's basically an electronic T400 from what I understand. Probably only made in Chevy bolt pattern too.<P>If you want overdrive, I'd go with the 200-4R for two reasons. First, the shift characteristics. Second, the BOP mounting pattern and size, which is the same as yer current Turbo 400. Way less complicated. You'll spend the same cash adapting a 700 as you would beefing up a 200. All in where you want to spend yer money.

[Guest]

my 455 has around 600 pd ft torque and I had a 700r4 the first one was just a used stock, which blew up right away, then i went through rebuilding it twice through two different trans shops, of course the trans blew both rebuilds, after the hassle of trying to get it repaired under warranty, which I did get, I sold it immediately and went back to the th400. If I could do it again I would have bought a brand new one built by someone who specilizes in these overdrive trans, such as Art Carr, one day I will do this when I get the money. They are not cheap this way, Last time I was qouted at 2500 bucks, but considering I spent this much anyway it would have been the best choice. I vote for the 200 also, the gearing is better suited for our cars from what I hear.

[The Old Guy]

The 700-R4 has a 3.05 first gear and a.75 overdrive. The 200-4R has a 2.76 first gear and a .67 overdrive. For your high torque engine, the 200 is the better choice. There are parts available to handle all the torque your engine develops. As stated in another post, Art Carr and others make high performance parts to solve the problems. The RPM drop with the overdrive and the lock up convertor is enough that my wife will ride in the GS again. The Flowmasters were too noisy with the TH400 .I was running 3300 at 70 and now it is 2200 and the decibel level is half what it was.

[Guest]

Romy,<P>For info about switching trannies go to the <A HREF="http://www.442.com/oldsfaq/oldsfaq.htm" TARGET=_blank>Olds FAQ</A>. Just a wealth of information, most of which should also apply to your Buick.<P>I recently asked one of my buddies about putting these newer trannies behind one of the old 454/455 engines because I've seen a few cars around here for sale with that setup. Before I continue I'll just let you know that this guy is a speed demon. He learnt to build engines from a guy that builds NASCAR motors. For the street he recently had a 482 BB Chev rollor motor with 8500rpm redline, camshaft on needle bearings, 4500 stall, NOS Fogger at the intake ports and NOS also at the carb. I was with him one day while we were doing 50mph. He stepped on the gas and just smoked the 21 1/2" Mickey Thompsons. That was without NOS!!! He's currently working on a 2500hp blown aluminum BB Chev for his tractor puller. He's had many BB Chevs over the past 20 years. Anyway, that's engines, not trannies. My point is, he knows how to make horse power. He also knows how to get the power to the ground without braking things. He's never had a drive train fail. His reply to my question was 'junk'. If you make any kind of power those trannies will eventually fatigue. If you going to spend alot of money building one of those trannies, you might as well put the money into something that is reliable ... a th400. <BR>If your building up the motor for mileage the newer tranny may stand up, but if it's for power it may not. If you decide to go with a th400 make sure you get the heavy duty sprag. Another one of my buddies and myself had almost identical 425hp+ 454's a few years back. I put mine in a 73 Caprice, he put his in a 67 Firebird. We both had 3500 stall converters. I had the heavy duty sprag put in my tranny, he didn't. We both abused the cars. My drive train never fatigued. He blew up his th400 racing a Buick GN. Cause of failure: standard sprag. <P>If you're looking for milleage, try changing the rear end gears. Just my .02 worth.<P>Tom