Uh Oh !! Bad knocking !!

What kind of 4" crank did you use? Eagle, Scat, other? J.Rob

mine was a scat hyper/cast set up

Have you ruled out flex plate slap or loose bolt yet?
Costs about ten bucks to change an oil filter. Cut it open, see if you struck silver (or tin).

no flex plates on a 4 speed ;)