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3.1 v6 to a 3.8 v6 supercharged


hutch321
05-01-2017, 02:06 PM
I have a 1989 grandprix Le and was wondering how hard it would be to do a complete engine and transmission swap. I would be going from a 3.1 liter to a 3.8 liter with a super charger.

DrRadar
05-04-2017, 03:19 PM
What do you mean by hard? It's a lot of work, but provided you have the tools (eg, engine hoist) and room and shop manual, the physical act of pulling and dropping the engine can be with moderate skills. I have pulled/dropped the engine once for a rebuild.

I can't comment on swapping transmissions because I haven't done that. I've heard it can be difficult to remove the half-axles.

I would be most concerned about the wiring. Does an LE have the same wiring harnesses as a GTP? Or will all the wiring need to be replaced, which means getting behind the dash and threading a new harness to wherever it goes.

Sounds like a sporty upgrade, but I'm not sure it would be worth the effort (unless your doing it for fun or education). The other option is to just buy a used low-mileage GTP.

Good luck.

Tech II
05-08-2017, 10:22 AM
The problem is the engine harness to the PCM, and the PCM.......it's possible the PCM(ECM) is the same #, but the prom inside definitely isn't......

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