I have a convex piece of metal that goes in the rear of the block behind the camshaft. How does it get installed? Its rather loose in the bore. Do I put it in convex till it bottoms out and hit it with a hammer? Or should it be tight fitting and I should be tapping it in (concave looking at it).

I have 2 of them and they're both this way (Fel-Pro)

Put it in the bore with a LITTLE silicone around the edges and smack it with hammer. It'll expand out and fit tight in the block.

My machinist and the experienced fellow that helped me do the rotating assemble both did not like that thing one bit, had me go and get the one that looks a lot like a standard expansion plug, only with a narrow lip.He put them all in with permatex #2 also.