400 tranny swap
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Joined: Oct 2007
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400 tranny swap
Hi out there thanks for pryor help .I have a 75 with the tubo 400 trans . I would like to put one in with the 3 speed overdrive.Can this be done by getting one out of a 86 2 wd truck ? thanks rich
Le Mans Master
Joined: Oct 2006
Posts: 7,123
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From: Gladstone MO
C3 of Year Finalist (appearance mods) 2019
The direct answer to your question is yes. BUT!! The overdrive tranny used in pickups in 1986 is a 700-R4. 1986 was not a good year for that trans. You would be much better off to get a 700-R4 trans from 1990 or 1992. The reason is that the General made some major design changes to that trans and increased durability by 100%.
Another option for your Vette, and a much easier bolt-in is a 200-4R.
Do a search, you'll get loads of info on both..
Another option for your Vette, and a much easier bolt-in is a 200-4R.
Do a search, you'll get loads of info on both..
Le Mans Master
Joined: Aug 2003
Posts: 7,720
Likes: 12
From: Chattanooga TN
You want an '89 up 700R4. Either a700R4 or 200R4 will work. 700R4 requires shortning the driveshaft. Do a search and you will find much info on both. Bear in mind that the 200R4 is only strong if you build it, don't figure on using a 100k mile trans and having it last long.
Instructor
Joined: Jun 2007
Posts: 128
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From: San Antonio Texas
What years are the good ones for a 200R4? What vehicles did they come in, I heard the GN(Grand Nationals, Monte's) were the choice---any other thoughts? And what is need for a trans to withstand 400HP?
Team Owner
Joined: Jan 2006
Posts: 37,637
Likes: 3,118
From: Crossville TN
While horsepower level is important to the survival of an auto tranny, the use of the vehicle is even more important. Instantaneous torque spikes are much more damaging than a constant 'high' level of applied torque. Chattering, sticky, big tires at take-off will kill a transmission quicker than a higher horsepower car with a driver that can control tire chatter. 400 hp is no problem for a THM-400; the others might need a sturdier torque converter. But if you go with an aftermarket converter, make sure it will operate with a lockup feature on the other two trannies (if you want to keep it).
