3.8 bottom end rebuild options
I have to rebuild the bottom end of my mom's 1992 3.8 Cougar and need some insight. Basically I have a perfect top end on the motor, car still looks and drives like it came from the dealership floor, original cold R12 AC, etc.
The motor has about 200K at the moment. I did the head gaskets 2 years ago and the motor was pristine inside, bore taper about 0.001", just needed to take 0.005" off the heads, minor clean up on the valve seats, etc. Head gasket gave way on the passenger side rear cylinder at the back and was shut right off so no overheating.
But that new fricking rod knock on cold start lets me know I am getting dirty again :-( I was hoping it was only the oil pump, but it is perfect inside as well I just found. The motor was always a little ping happy, so I am expecting to find most of the rods out of round.
What are the options for the bottom end only? Can I drop in a 4.2 bottom end keeping the 3.8 oil pan, etc? Don't want to do the split valve stuff, this car doesn't get used much anymore as my parents are retired, so don't want to waste money either. Basically a stock rebuild. Whats the word on replacement rods, pistons, etc., if I just rebuild what I have? I am thinking a new set of stock bore pistons, re-worked rods, rings, bearings, etc.