Transmission

[ChevyPower18]

I have a 94 Cavy 3.1 with a 3 speed automatic transmission. I know they also make a 4 speed automatic. Has anybody made the swap from the 3 speed to the 4 speed? Would it just be a swap and go, or would other components need to be swapped also such as the computer?

[3400-95-Modified]

4 speed is electronic unless you go with the 4t60 non electronic version... Now if that swap has been done I dont know, I would assume you would need some motor mount work done unless the 94 cavi uses the same side mount.

Either way I can't imagine it being a swap and go project.

[1988GTU]

The 4 speed (non E) uses W body mounting since those transmissions were found in the TGP application. I don't know of anyone currently with a successful swap, but I would imagine it is more possible to accomplish than a 4 speed-E trans swap. The 4 speed would be better for highway use, but imo, when you compare the 3t40 with the 4t60, they're both pretty weak at handling more hp/tq. If one were to want to have just a street/performance trans made out of the two, I would suggest the 3t40 since it doesn't weigh as much and much simpler design. If you're looking for highway use with performance in mind, then the 4 speed is the way to go IF you're willing to chop/weld in some new mounting brackets.





.02

[bszopi]

4T65-E swap has been done in a 90s J-body, so it is entirely possible. There is a thread around here somewhere about it...

http://60degreev6.com/forum/showthread.php?t=37952&highlight=4T65e+swap

[TurboGTU]

I think its easier to gear the 3spd for overdrive than to swap a 4spd. I've been tossing more than 270lbs of torque thrugh mine.

[asylummotorsports]

I have had pretty good luck with the 3t40 with the one exception being the failed 3.94 unit.

However the guy who builds them for me can't believe they actually last more than 10 runs, LOL!

And I have been hurting converters lately after about 30-40 runs.