I took your advice and used enough helicoil to match what was there in the first place. You point about the proper stretch of the bolt made me think. I did consider using a stud but before helicoiling I realized there was enough meat for a helicoil but not for the next larger thread. Torquing the cap down felt great I almost feel like helicoiling the rest. I believe your assessment of the tap being the culprit to be correct but, I think the lead in on the hole was really to blame causing a timing problem between the original threads and the tap. Thanks for the help. Neal