[nhramnl]

It's not a Bowtie block, is it? Because with those, engine builders have been known to forget to reinstall the galley plug that feeds the cam tunnel, which causes seemingly unexplained, but repeated (until you figure it out) cam bearing and lifter failures, due to lack of oil. Obviously, if the camshaft isn't getting any oil, the pushrods and rocker arms won't, either.