[Tom Goldman]

Alan, I agree the 400 is one tough case ,but lately the supply of used cores from the salvage yards seems to be getting pretty beat up.
I've had several salvage yard cores recently with cracks showing up in the bell area after they were cleaned.

The other issue I've seen is from cars that are big wheelstanders with no mid plate. i.e. Stock and some brackets cars. Not that many racers run them in Stock anymore.
They seem to have more issues with cracks than others.