Water Jacket side plate stud woes
 

Good afternoon, all. I'm replacing my side plate, after a hole in my head (also being replaced) leaked water all over it for too long. I'm using four of the stud kits from Moyer to swap all the bolts for studs (most of the bolts' lower halves were merely pockets of rust anyway).

I do the dry run, then install the first pair of studs with JB weld on the plate. I am tightening both studs, switching back and forth to keep it even, wondering when they're going to start resisting, when suddenly, one snaps in half. Pictures: https://photos.app.goo.gl/tVzUVo7xURWXjoGr5

The JB weld is drying as I am trying to figure out what to do- eventually it occurs to me to try and get the backing plate out so I can start over with a new kit, but it won't budge. I realize later that that's because I had screwed the stud entirely through the block wall, and was jamming it up against the piston bore (I guess is what that's called?) inside the water jacket. When I snapped it in half, I'd left half the stud jammed tight between the bore and the backing plate, holding it firmly in place.

I waited til the JB weld set, then tried drilling and using a screw extractor. However, i am working with very little access on that side, and am afraid my hole isn't centered, and that the screw extractor might not be working against the stud, but the backing plate itself. I'm too scared to really put any oomph on the screw extractor.

I got the other 7 studs in just fine.

My questions:
- is it possible I'd be okay with just 7 good studs, even for just the remainder of the season?
- If so, should I fill the hole I drilled into the broken stud with jb-weld?
- If not, should I try and tap the hole I drilled into the broken stud? Or put some muscle on the screw extractor?
- Finally, where do I put the aviation sealant? Do I brush it on the gasket itself, both sides? The studs themselves? Both?

Thanks in advance, friends.

If it were me, I'd leave the broken stud stump right where it is and stop messing with it. I'd drill a new adjacent hole, 5/16"+ in the side plate and with the side plate in place as a drill guide, a smaller hole into the block side of suitable size for a 5/16"-18 tap. Position the new hole just beyond the repair plate so you don't disturb it. That way the side plate will be nearly as secure as original.

I appreciate the advice. I think I may put the plate on as-is, but remove it and do exactly what you suggest if in fact it leaks. But I'm still not sure.