Replaced intake manifold gasket with gm aluminum gaskets and valve cover gaskets. Also injector o rings. upon initial start primed fuel system, disable fuel pump cranked engine all seem normal. crank with fuel a horrible metal clanking banging not really sure what it is sound like its coming from upper motor. pulled valve covers to see if anything was in by valves found nothing. crank with valve covers off no fuel all seems normal. crank with fuel noise again. really stumped here any assistance would be taken
thanks steve