700R4 Source for '56 GMC?
 

I am in the process of planning to install a 700R4 into my ‘56 GMC 100 pickup that currently has a 455 Pontiac coupled to a TH400 followed by 3:73 gears. Have talked to some of the vendors but looking for feedback from the forum. Truck is just a cruiser with maybe 300 HP/400 lb-ft of torque fueled by a Quadrajet. Prefer to buy a good rebuilt unit from a reputable source either local or the ones advertised such as Phoenix, Performance Automatic, TCI, Monster, Transmission Depot, etc. Aware of the issues with the 700R4 and the parts needed for the install but would appreciate any information from those who have done the swap.

Re: 700R4 Source for '56 GMC?
 

I think you need and adapter to make the 700r4 work behind the 455. Not up on my Pontiac motors but thought they were different. I think some mid 80 olds had 700r4's with same bolt patterns. The better 700r4's that were built were the 87 and up models.

Re: 700R4 Source for '56 GMC?
 

For that hp/torque range - TCI Streetfighter 700R4

Re: 700R4 Source for '56 GMC?
 

i have a http://www.phoenixtrans.com/ 700r4 in truk, i suggest you email them to see what they have
install was plug and play and has been in truk for the last 36,000 miles without any issues

Re: 700R4 Source for '56 GMC?
 

I would suggest a 2004R. The bellhousing fits BOP without adapters. The first gear ratio of the 2004R is more appropriate for the high torque of the 455. The transmission is inherently stronger than the 700R4 and it can be built to survive at very high torque levels.
https://www.jalopyjournal.com/forum/...ission.566029/
http://cpttransmission.com/2004R_trans_2to4.htm
https://www.hotrod.com/articles/ccrp...mission-build/
http://extremeautomatics.com/th2004R.php#th2004r

Re: 700R4 Source for '56 GMC?
 

I can't help with the swap. But have used Performance Automatics with great success. They aren't far from you either. Go check out their place in person, it's impressive. Good luck on the swap!

Re: 700R4 Source for '56 GMC?
 

I don't believe they ever made a B-O-P pattern 700 r4 case. If you have to have that trans rather than a 200R4 buy the thick adapter plate with the spacers for the converter snout and converer bolts. I've used both and the thin plates with the nuts welded to them leave a lot to be desired.

They run the 200R4 behind some real stout engines though.

Re: 700R4 Source for '56 GMC?
 

I do not believe so. I have a 700R4 training manual from my dealer days. I once posted to a forum that a 700R4 may be available with dual pattern bell housing based on a drawing in the manual. A Hydramatic plant manager on the forum quickly corrected me. "No BOP patterned 700 was built." The only non-SBC version is the 60 degree V6 version from 2.8 F cars and S10's. If you have to use an adapter, the thick adapter with proper converter support is the only way to go imo.