Installing a 700r4 in a 81 Burban

[81 Big Dogg]

I have a 81 GMC Suburban with a stock 454. I am planning on swapping the existing 350C with a 700r4 to get OD. This is a DD little to know trails, some sand trails in Outerbanks but for the most part its a Hiway Queen. I know I have to beef it up to hang with the 454. My question is are there any electronics involved in this swap? At what year does electronics come into play with this trans? I want to understand what i a looking for when i go out an seach for it. Thnaks in advance for your help fells!!!

P.S. If anybody has a 700r4, I do have a good condition TH400 and\or a 350C (35k since rebuild, has shift kit) I would trade. Just thought I throw that out.

 

[PavementPounder]

I'm doing the same thing to an 87 that already has the 700r4 and found some information regarding affixing the TV cable bracketry to the TBI just by searching this sub-forum, but I'm not sure what to do about the electronics, either. People I've talked to suggested stand-alone computers that the hod rod crowd uses, but that can't be the only solution for a truck that already has the electronics.

I have a diesel-spec 2wd 700r4 sitting around that apparently does not require certain controls, but I'm not sure how that might help. I initally picked that up to swap into my old Pontiac conv't since it was "dumb". One of those might be a better candidate for a carb'd 454/700r4 swap?

 

[Greg Ducato]

The 700R4 only requires lockup in 4th gear to prevent overheating of the converter and max lube flow. It is fairly simple to wire these up internally off the 4th gear pressure switch so all you will need is 12 volts into the trans for automatic 4th gear lockup. Unfortunately, this method means the converter will always be locked in 4th so it won't have the same driveability as the later TPS signaled TCC systems. When pulling a long grade in overdrive you may not want the converter clutch engaged so you can run a toggle switch in the circuit to turn it off for torque multiplication. Or just feed it more throttle and it will drop to third gear and unlock the TCC at the same time automatically. In addition, you can purchase a non lockup converter and modify the pump to operate as a 4 speed non lockup transmission. Be sure you use a low stall converter with this and a big cooler if you choose this route.

 

[81 Big Dogg]

I want to go with the OD trans but i am worried it wont holdup behind my stock 454. i do more highway driving than off road. after a good rebuild how well do you think it will hold up.

 

[4X4HIGH]

A good built 700R4 will stand up to some decent abuse. I've been running my built 700R4 for about 8 years now with no issues. The last 2 years it has had a 400hp/500+ tq 355 in front of it and i'm not easy on the skinny pedal. The biggest thing about a 700R4 is to keep it cool. They live confortably around 170*-190*

 

[4xcrazy]

run the little vacuum switch that's used on say an '83 model truck with the same trans.

 

[Greg Ducato]

run the little vacuum switch that's used on say an '83 model truck with the same trans.

Those actually work pretty well on a near stock engine with good vacuum. The GM part# is 14032087