The oil pump will likely turn easy by hand, but when it is up against pressure, then they become harder to turn. Which is why I suggested driving it with a drill. Monitor your oil pressure, does the pressure release work correctly. Old skool was 10 psi per 1k rpm, but now we put lighter springs in to obtain about 35-40psi, any higher eats HP. Jerry suggested the dizzy body is hitting the can? Is this possible? Missing shims? Give me a call if ya like, work in on z interior. Mike.