Got a 93 park avenue with the series one 3800. I ran the motor dry on coolant, changed the head gaskets and had the heads planed and checked for leaks. I put new head gaskets in, and head bolts, along with the rest of the top end. The motor ran good for a few days, now its got low compression in cylinder one, and a bad miss that pretty much shakes the car at idle. It smooths out under acceleration, but its rather shaky in OD at 80 kph, but smoother at 100 kph.

Motor'* got 367,000 kms. I have a 91 lesabre just sitting unused, with the same 3.8. Its got arounds 140-150,000 kms i changed it years ago due to a blown rod with this current motor.

I wonder if these engines are pretty well interchangable aside from switching a few parts? Intake and plenum will definitly have to be switched, the PA has a plastic intake. Noticed how it was different from the series 2 plastic intakes, the egr on the series one is well sleeved and away from the coolant. Can I bolt up my PA exhaust manifolds to the 91'* motor? That and aside from the mounts, the heads should basically be the same?

Never mind..

Its still running, i haven't the time to do a swap, so i'll drive her till she blows. I'm travelling 240 kms a day, and i haven't noticed too many issues on the road, just a little shaky in gear at idle.. I am pretty sure the block and heads are the same on my 91 if that need arises.. Otherwise I'm gonna start scouting some yards for a donor car for a possible SC series 2 swap, which ought to be fun.