Precup cracks

[tom yuenkel]

I am in the process of prepping my 1991 heads with 240000 miles for a valve guide and grind job, but before I dropped them off did I disassembled them to inspect. I found no visable cracks between ant of the valves but what I did find were cracks in 5 out of 8 precups at the corners of the hole leading into the cylinder. Are they ok to reuse, is this normal or should I not risk the reuse of these parts?

[john8662]

Rarely can you pull down a set of heads and not find cracks on the pre cups. The cracks are acceptable as long as they do not approach the ring or gasket line where the gasket seals accross the cup.