Bad lifter

I used plenty of assembly lube and I have castrol 20/50 oil in it, ran it at 2000 rpms for 1/2 hour. maybe I should use lighter oil??

I put a 484 lift purple shaft in it, any suggestions on what cam I should or shouldn't use? The engine is a 72 340 bored .030 over with a set of X heads.

Nothing wrong with the cam choice. You might want to check the spring pressure before you break in another cam. Vary the RPMs a little bit more. Give it another go. Good luck.