honestly, by the time the old Z-motor hits 150K or more, any oil that is still in there after 3-4K miles is good.
I would spend nothing more than walmart super tech on sale and check it.
if you have sludge (you dropped the pan to verify this?) then you have the expected intake manifold seepage at the rear crossover port. spend an afternoon and change this out and be done with it.
if the body is good and none of the bushings or mounts are shot, consider a reman 4.3. every once in a while advance runs a special from 'recon' on them for cheap, with a warranty.
I would spend nothing more than walmart super tech on sale and check it.
if you have sludge (you dropped the pan to verify this?) then you have the expected intake manifold seepage at the rear crossover port. spend an afternoon and change this out and be done with it.
if the body is good and none of the bushings or mounts are shot, consider a reman 4.3. every once in a while advance runs a special from 'recon' on them for cheap, with a warranty.