With my 2005 AT, am I going to see a huge difference if I install the 3.917final drive? I'm assuming if I install a torque converter and a tranny cooling system, the results will be even better.

Anyone have the final drive?

 

Just remember you'll need to source a 6MT differential to start with. You won't be able to use your stock pumpkin. Makes the install easier since you won't be without your car as the shop does the build, only have to swap pumpkins. Its a good time to consider installing an aftermarket diff as well. But you either have to find a used one or pony up the $1250 for a new one.

You should see substantial gains, I'm going through a build for this right now. ISMSOLUTIONS has it, search his name. He's been a wealth of information if you find the posts.

 

I thought that all I needed to do was:

1) Purchase the 3.917 ring and pinion set.

2) Then, pay for the install.

The guys at Jotech said they'd do the install for $600.

Is this not the proper way to do it? At least, can it be done this way if I cannot find a 6MT pumpkin?

 

That would be the case if you had a stock 6MT pumpkin to begin with and had the 3.5. 6MT and 5AT drive rings are different thicknesses. 5AT is 10 mm thicker.

I can't think of a way you could do it without a complete rebuild of the inner parts of the pumpkin if you tried to do it on your 5AT rear. Maybe JoTech knows something I don't, but I'd hate to see you with a disassembled pumpkin just to find out its not going to work. Do they know you have a 5AT? Or are they under the impression you have a 6MT.