Its an old engine, and i know from experience that once the m***ive oil starts rolling, time is critical, get a new kit on the engine, and youll get another 50 years out of it. (and run strait pipe..nothing sounds like a y-block un muffled)
Yep time is ticking on that motor. get the kit and get it done. that is a strong *** motor and you can get a long life out of them but you gotta treat them right...
If it isn't smoking/fouling plugs and has good compression, you need check the draft tube. Take it apart and give it a good cleaning. Make sure the little oil return tube is there and not clogged. Straighten any bends in the mating surface of the draft tube and also make sure the top canister fits correctly. Make a new gasket and reinstall the draft tube on the cleaned mounting pad on the side of the block. Hopefully, you'll now have a clean and happy Y-block!