Can the holes for head bolts be retapped?

I’m looking at buying a b18c block from someone. He said that one of the “holes” where the head bolts go in appears to be stripped. My question: Assuming that it is stripped, how hard is this to fix? How big of a deal is this? Expensive?

I’m trying to make a decision on this block. The price seems right and the guy seems trustworthy but I am trying to figure out if this could be a deal breaker.



i know on steel u can rethread the hole… aluminum your might have to move up a size (and get 1 missmatched headbolt)

i havent had experence with aluminum tho… just steel

yeah you can rethread them.

A friend stretched his head bolts and it stripped the holes so he had to rethread them. I think he had to drill out the hole and rethread it. His sn is gen2ls/vtec if you want to shoot him and email. I don’t think it was expensive but just took some time to do all that work.


hmmm… Sounds ok… Do I have to do as Radzero said and use one oversized bolt?

I’ll try and get a hold of gen2ls/vtec

we get customers in with this problem a lot. it’s usually caused by using the wrong size head bolts/studs. what we use is steel inserts. it’s like using a heli coil but a lot stronger and you can still use your stock bolts/studs. part of the process to installing these inserts is drilling out the old threads prior to installing the inserts. there has been many mistakes we had to fix from poor machining/installation, due to the fact that the threads are about 5 inches set in the block. drilling the holes straight is very difficult and crutial. you wouldn’t want to end up with a crooked bolt/stud. i recomend, if you decide to go this route, send it out to a machine shop to get it done. or if you don’t know of one, the cadillac norstars have the same size and pich as a integ.(11x1.50) and have the problem of stripped head bolts enough to where the nearest cadillac dealer should have the repair kit on hand and should be able to fix it for you. there has been times where we’ve run out of inserts and had to call the cadillac dealer to buy some.