OK, thanks, I didn't know about the spring loaded valve. Looks like I have to actually go do some work today, so I can't get to this until later. But since I am pretty sure the fuel pump is the culprit, was there a difference and does it matter if I replaced a glass bowel pump with a sealed version? Could the later model have higher pressure to support a bigger engine and possibly the Rochester B? I swear this engine is cursed, but ran pretty well, except for the knock, until I put this pump on.
