I have the GN1 heads that have the receiver grooves for the wire lock gaskets. I blew my engine a couple of times and I just found the receiver groove is worn flat in a section. I was wondering if I could have them machined down and then put new receiver grooves in. If I can't, can someone suggest another fix. Some people told me that you have to have the hole head welded and then remachined and then have the receiver grooves put back in them.