upgrade th700r4
 

Hi,
Im building a custom car, Hudson -53 and im using a H1 6.5l diesel engine and i have a Th700R4 trans with serial nr 4Y9060 wich should be a Corvette trans from 1984.. im a little worried about the massive torque from the H1.. does anyone have a tip how i upgrade it to last.. im not gonna use it and play, gonna try to make a nice car for long trips.. would Transgo 's reprogramming kit 700 2&3 be a good idea ? And what does it really do to the trans?? Is there a difference between a diesel and gas engine, govenour ?? Is it possible to make forth gear go into gear at 50miles/h ?? Id really appreciate some good idea's to clear my mind

Re: upgrade th700r4
 

The 1984 700R4 doesn't have any of the later model year factory improvements built into it. I would consider finding a 700R4 from 1987 and later.

I don't think that a shift kit alone will do much for turning a 700R4 into a heavy-duty unit just by itself. My understanding is that the 700R4 has a lot of issues that need be addressed especially when using it in applications that it was not designed for.

If you look at the parts list for building a HD 700R4, you'll notice that there's a lot more parts than just a shift kit.

https://www.700r4l60e.com/store/prod...&cat=19&page=1

The shift points are dependent on road speed and throttle opening. The 700R4 in my Camaro shifts into 4th around 45 MPH at light throttle so this shouldn't be an issue for you.

There's another issue to consider if you're going to use a 700R4: you'll need to fabricate some kind of linkage to adapt the TV cable from the transmission to the throttle body on the engine. Get this throttle opening vs. cable pull geometry wrong and the transmission will quickly die a painful death.

It might be easier to use the transmission that was originally bolted to the diesel (unless it was the TH400) along with the power train electronics.

Re: upgrade th700r4
 

Hi Paulo,
Thank you for youre reply..
Aha ok.. i had 6.2l in the car before so i made that linkage to the TV cable and it worked great.. but the H1 is something else.. So they have issues theese early trans 1982-86.. maybe i have too look around for a newer 1987-.. Original on the engine it is like you say th400 with the computer