Hi, my shop was remvoing an after market oil filter bracket and snapped off two head bolts. What size,and grade are they and what thread count do they have? I assume they are ASME threads?
This will slow down mt resoration a few days I assume.
If you can get the old ones out, then you can order the correct ones here:
Terrill Machine, Inc in DeLeon, Texas. (254) 893-2610 (no website)
I honestly think that if you removed two of the bolts that were in sequence, you might want to consider taking the head off and replacing the gasket. I don't really know if the seal will remain intact, but, I am not a pro, so you probably know better than I do if you have a chance for a leak at this section of the head.
Good luck - let us know how it works out.
My favorite method for removing broken head bolts is EDM (Electrical Discharge Machining). Others will have their favorite methods. Any machine shop that does a lot of engine work will have an EDM machine (or at least know where there is one.) Google EDM for a description of the EDM process. You will need to remove the head regardless of extraction method, so order a new gasket and all new head bolts from Terrill Machine. Ez-Outs typically don't work and often break off compounding the problem, so I'd avoid them.