Re: What kit/engine to buy for fairest price?
You likely won't be able to push that pin (called the "bucking bar") in by hand, you need the camshaft and lever attached to have proper leverage to get it to move. The cover should fit on over it though, the camshaft flat should rest against it and the cover should mount up flush. Can you not do that? The ball bearing is what the bucking bar bears against, order from outside to inside is camshaft, bucking bar, ball bearing. It should be able to spin freely.
Should actually be 66cc if being sold as an 80, not 49.