I have a 4.3L in my 92 K1500 4x4 5 speed that either needs to be majorly resealed or replaced. It has about 205k miles on it right now. It leaks a fair amount of oil from the intake and possibly the oil pan and crank seals, it also burns enough oil that I can smell it on occasion especially after first start up, which i believe to be mostly worn valve stem seals. Also when parked on an steeper incline like a boat landing in 1st gear the truck will actually roll down hill by turning the engine over. I don't know if that's normal with that heavy a truck even with a new engine, but I can't help but wonder if it just has generally low compression. I'm fairly confident a compression test would show all cylinders fairly close since it runs quite smooth and well, and I'm not sure the number itself would help me since they never seem to read what the book says even with different gauges. I can't figure out a good way to turn the engine over by hand to do a leak down test either, usually the bolt on the crank just turns in my past experiences with this sort of stuff. Oil pressure is about 30 psi driving or cold, and 20 psi warm. Maybe I'll just do the top end seals and hope that takes care of most of the leaks, I fear if i pull it out ill be tempted to pull it apart and itll get out of hand. If the engine is out, where do I stop replacing? The truck has a ton of stuff replaced on it already so it might be worth a rebuilt engine, not sure if I could get much better with a used one if I could find one. Also considered V8 swap but a complete donor vehicle of same year would cost too much, any any other way is a pain to get all the parts. Plus I rather like the gas mileage of the 4.3, and it has more than enough power for 90% of the things i do with it. It's just rather slow sometimes. As you can tell by my rambling I'm just going round and round confused.