I have a 1983 Firebird s/e... i am trying to install a 1989 motor w/ the TPI setup. I have the harness and all computer accessories necessary for the swap, however.... is there an easier way then checking diagrams for the 83 body and cross referencing them with the 89 motor... an easier way then the cut/splice method? I heard about a painless wiring harness kit, but i dont know what that is? any help is greatly appriciated. Thanks in advance!

 

In this case you might benifit from a painless wiring harness. just use the existing harness to run the temp, oil sensors, to run the alt and ac. The painless will get the engine running only with no reguard to alt and guages. So hopefully you didn't get rid the old harness yet.

 

yeah... i see what your saying... however would i still have to cut and splice all the old wiring on the 83 car to match up to the harness for the 89 tpi?

 

I swapped a 350 TPI into a 82 Malibu using the stock wiring for most of it. The engine harness to the computer stayed in tack. What you need to to is get both the 83 and 89 wring dirgrams together and mark what goes into the fuse block, ing. sw ect. I found that GM makes it pretty easy because alot of the color coded wires where the same. The wires can be removed from the OEM connectors with terminal tools the NAPA sells so the swap will look very clean.

 

You'll need to check on the speedometer too. Your 83 might be a cable driven with a electrical connection to the computer and the 89 computer might need a different type of signal. When I did the swap I used the 88 Firbrid's engine , trans, and dash with the electric speedo, tac and gauges .

 

You're going to run into alot of problems cutting and splicing stuff. The best way that I've found to do a swap like you want to do is just gut the entire car including the dash and just re-wire the complete car! I know it sounds like alot of work(which it is)but in the long run it'll be better for you and the car! I did the same thing to my 86 T/A--swapped everything from my 89 formy(ENTIRE harness--body, motor, dash, lights--all of it)-even the vats works!
Don't have any shorts either!