I had a leak awhile back, and found 3 broken studs. 2 I got with vise grips, 1 was broke inside. I couldn't get a hard enough drill bit to extract it, so finally I got p'd off and took a hardened rasp from Grainger's and went crazy. Rethreaded to 3/8" and put a 1 1/4" bolt in the hole. $72 for gaskets and new studs/nuts- $30 in useless (for this job) drill bits.