whats the differance in these trannys will a 86 corvette 700r4 fit in a 86 trans am? if not what is it that makes the corvette tranny better and can i put that in my trans am's tranny?

 

I just bought a rebuilt tranny for my 1990 GTA . When I picked it up it did not have the tailshaft housing on it, they gave me a new rear seal, housing gasket and speedo gear gasket. I did not have mine out yet, had I brought my tranny with me to pick up the new one, they would have put MY tail housing on the new one.(that is why they gave me the stuff I would need to change it) I installed the new one last weekend, after putting my tail housing on it. Everything was going fine, all I had left to hook up was the cross member and put the driveshaft in, I crawl back under the car with my tranny mount and the two bolts, hey, there are NO FOCKIN BOLT HOLES for the tranny mount! I look at my old tranny and the holes are in the tranny case. New tranny, no bolt holes. So I call the shop where I got it to explain my problem, as it turns out they gave me a Corvette trans by mistake. The vette trans has the crossmember bolt holes in the tailshaft housing, 3rd gens have them in the trans case, I suppose you could put the vette housing on and relocate your crossmember, but, WHY ? Now I have to drop the trans and take it back to get the right one . I did put the crossmember back on to hold the rear of the trans up and put the drive shaft in to keep the car from rolling out of the driveway, and as far as trans length goes, the driveshaft fit perfectly. There is just nowhere to hookup the mount. FYI, vette trannys have a big V on both sides of the case, I thought the shop put it on there to identify there transmissions, nope, factory mark for-Vette.

 

ok so besides the bolt holes whats the differance performance wise between the two?

 

It should have an updated servo so it will shift firmer. It will also have a higher stall converter, if your getting that. There may be a few more but I'm not sure exactly what.

But, if your looking for a better upgrade, see if you can locate a later year'd tranny. From what I can remember, the 85?-88 700r4's had a few problems that were fixed on the later years.

Hope that helps.

 

That would probably be the best thing to do, get an 89 to 92 third gen tranny put in a vette servo, and a higher stall converter. I doubt there is much else different besides the case. You could pm Dana at Probuilt and I am sure he would know what the differences are.

My new tranny waiting to go in!

 

I believe what he was saying a bout it looking stock my friends dad has a stock looking tpi till this day that will roast some 19 inch at 100mph and he still has the vette it has asm runners on it some cam that shakes ground when you start it and I know the torque is off the charts sorry for the reviving this just added my two cent I even got a pic of his intake and running ford 24lbs racing injectors

 

Not stock by any means but don't underestimate a tpi setup

 

I'm replying to this old thread seeing that 1990GTA was active just the other day.
What was the end result of this Vette transmission installation in your Firebird?