hello ... I have a carbeurated 4.3L from a pre 1990 S10 ... I want to put a "true" HEI distributer on it and put it in my 1999 Jimmy 4X4 ... my question is will the transmission shift properly ? Should I leave the HEI dist that is currently on the donor engine (it has a 4-pin jack coming out of the base which I assume controls the advance and has the tachometer info) - is there a way to splice this into the current 1999 wiring harness so the trans "knows" when to shift ? can I go with a straight HEI w/ vacuum advance ? (thats what I prefer) - what do I have to do in order to make it so the computer controlled transmission shifts properly ? can it be done ?? thank you , marc

 

Short answer - No. Slightly longer answer - not without a lot of work and/or a stand-alone controller for the 4L60E.

Also, there are a LOT of systems in the truck that communicate with the PCM so if you do away with the stock PCM, you will likely have many other things that won't work.