[wagonman76]

You got the 3.4 DOHC? Those are a royal pain to work on and the reliability is not so great. I'm all for the 3.1 MPFI. I too have had several and they are tough as nails, have boatloads of torque, and are very good on gas too. That engine with 80k is just a baby.

I am pretty sure the DOHC engine has other components that the 3.1 does not have (cam sensor at least). Also an issue would be the transaxle. The 3.4 uses a 4T60E which is electroncally controlled by the computer. The 3.1 uses a plain old 440T4 which is vacuum controlled. Some guys have done this if you wanted to use your existing transaxle, either with some other choice or chip, or a hacked chip.

But honestly, the 440T4 is more reliable, they are very tough. The 4T60E you have now is not that great, it has valve body issues, especially the early ones like you have. I think your best bet would be to swap in the engine, transaxle, harness, and ECM from the donor car. Keep the donor car till you're done in case you need any odds and ends. Both engine and trans will bolt right in, and should use the same driveaxles and mounts.