I'm going to be swapping a 87 2.8 to a 5.7 with a ccc q-jet, i know how to swap everything except the computer, i'll have the engine wiring harness and the computer, what do i need to do to install it? change the entire harness for the car? (i hope not) i posted this question on the ecm board but had no help. Also GM has a HO350 package, they list a chip for their conversion, would i need a new chip?

 

You need to have the big harness that goes to the passenger side fender liner and into the passenger compartment. If the donor car, ECM and all are the same year & model as the car it's going into, it's just a matter of pulling the V6 ECM & harness out and putting the V8 harness and ECM in. I changed the entire dash harness as well, but that's because there was a 4-year difference between the donor & driver cars.

Don't forget that the V6 & V8 tachs are different.

The chip isn't absolutely necessary, but you should verify that the HO conversion kit ECM and the one you have are the same part number. If not, Jet can provide you one that will help. I think ignition coil and module are more important than the chip, though.

 

Thank you! the year of the donor car is a 86, my car is a 87, i don't have a tach, so that's not a problem. The GM HO package is for a 82-87, but i just looked and what GM does is give(sell) you a new ECM and chip, so a aftermarket chip would be the cheapest way out.