RE trans issues. the designation of 4L60E is misleading to me. It makes you think that they are all the exact same trans. While they have some mechanical similarities, there are many subtle differences. The E stands for Electronically controlled and that is only one of the fundamental differences. Pulse Width Modulation and so on. I hope a trans expert will jump in here and help with this complex topic.

 

Rmitchell , what I was suggesting is that if the donor 1994 Impala is an SS model, then the engine is an LT1 5.7 L V8 and is not a Vortec V8 from the same family of Vortec engines that our .4.3L V6 are. The F.I. spider , the distributor, and other systems would not be similar.Therefore the transplanted LT1 would require a Impala SS trans, harness, and computer to supplement the LT1 V8.
. At one time , there was a former GM engineer who was providing a kit to accomplish such a transplant. That was 20 + years ago and I cannot remember his name or his company's name. Try googling it and see what you find. I want to say it was something like Spear Co. Engineering.

 

Right on brotha