[Ironangel]

Originally Posted by guyryan100

Thanks Iron, that matches my own research and I think I'm comfortable attempting it since I don't have to bore a larger hole - its just tapping an existing hole.

My one question is, at the bottom of the hole is it open, meaning metal shavings will fall through, or is it closed? I've read its both, I think that depends on what heads you have. I have basic iron heads.

Knowing that jig exists is a big help, I have a fighting chance of not screwing it up.

Ryan

Some holes do indeed penetrate the water jacket, no worries because if some cuttings do fall into the water jacket they will likely rust away or find a home at the bottom of the block or radiator. If you coat the tap with wheel grease and take your time cleaning the tap and regreasing it two or three times before reaching the final depth, there will be little or no cuttings falling into the water jacket. When you pull your first stud you'll be able measure the depth of the hole. Measuring the length of the screw in studs from the bottom of the hex to the end of the 7/16-14 threaded end of the stud you'll be able to gauge your tap depth. The kit I posted does not contain a "bottom tap" or any tap at all, you'll have to purchase a tap or taps. (I'd get one of each, a bottom tap and a self centering starter tap if money allows) The aligning pin pictured with the kit is used to align the tool when working on heads with no stud in the adjacent holes. The tool should be centered with either an exiting stud or the pin. Use the big hole for aligning the tap. Use a grade 8 flat washer on the tool when your pulling the stud, nut wont mar the tool. I think that's it..."Walk in the park"