Bought used 117,000. Used a little oil and coolant would need irregular replenishing, odd. Every now and then a sticky lifter, then when I added Lucas to the oil all H--l broke loose, literally. Next oil change there was so much sludge in the sump the oil would not drained. Long story short, the sludge clogged the oil pump suction and w/o oil pressure things were not going to get any better. Found a used motor (100,000) miles, swapped out. Better engine, more power, no oil consumption, coolant OK. I'll probably drive this truck for another couple of years. I like it. I think the sludge was related to the coolant loss. As it was infiltrating the crank case and slowly evaporating out?
Ride, Power, XM, XM, XM. Goes great in deep snow.
Maybe the aluminum head iron block matchup was the problem.