You don’t have enough useable parts for a 300 buck kit.
You for sure need a cam and lifters. I don’t like the looks of the rocker shafts, and as bad as they look, I doubt the rockers are any good. And one end of the pushrods are blue. That’s heat from lack of oil.
You need to gets eyes on it from someone who looks at this stuff regularly. A plug may be missing somewhere, a plug may be installed somewhere it shouldn’t, who knows.
Something ain’t right. I’d mic the crank and see what size it actually is, and see if it will polish up.
EDIT: I wasn’t looking at the rocker shaft. That’s was a close up of the pushrods. I hate looking at pictures. You need to look at the shafts and rockers and see what they look like.
