I think i broke rear main bearing

Dan the man said
I've never seen heli coils hold up when used in a stress area. I have a friend who had a block where the machine shop used heli coils in the cylinder head bolt holes, it never held a headgasket after that. The cap is a breeze to install, the problem is having the block align honed

Well then, we will see how I do. I’ve got a BBC on the dyno that has a helicoil in a head stud hole.

I’m betting it won’t fail.

The chances of fitting a main cap and cleaning it up with a line hone is slim. You have to line bore them.