408 valve train noise
the pushrod thing is a problem that I already encountered. had to enlarge the holes in the heads because the pushrods were hitting. I bought these heads used and the old rocker arms and pushrods were junk because they would hit the side of the head and as the cam lifted higher they would come out of the socket of the rocker arm just enough to cause a rocking effect on the socket and make them egg shaped. as you can imagine it did the same to the pushrods.