Thread: 03 engine into 02 GP... Direct swap?

it should swap right in, the only thing maybe the trans plugs, 03 they did some changes. its nothing you can work around.

im sure BillBoost37 has a write up if you need to do this.

If you did the complete swap, you need to use the 03 pcm, your 02 pcm wont work with the 03 trans.

and the engine harness as well?

Not sure on that part, I wouldnt think anything would change from 02-03, besides the way the pcm controls the trans.

Newer updated parts, hardened 4th gear, valve body/channel plate difference I believe.

Besides the 4th gear shaft, not really no.

They all tend to have the same problems, just 03+ will likely never have a 4th gear failure.

One difference is that they put the gear selector switch inside the trans, vs bolted onto the top. The old style switch will still bolt on though, and you can use your stock harness with it. You would also need an 03 PCM (hardware) and a custom tune, starting with the 03 base cal. Not a bad swap, I ran an 03 trans in my 99 regal for 5 years or so, and the cars still going strong!

-Rob

Originally Posted by darkhorizon

you dont need any 'custom tune' but you would want to put the 03 file on.

My bad, your correct.

I was basing that statement off running an 03 trans with an older motor. If you have both an 03 Motor and Trans, you can just use a stock 03 PCM (Hardware and Cal).

-Rob