Quote Originally Posted by Ken1960 View Post
I think my problem might be the vent no bigger enough, magna fuel said I need at least a 8 n for vent , all I have is a 1/4 vent line that might be why it is stumbling a little on bottom only,but might be why fuel pressure is up and dn , the fuel pump I have is a pro 500 suppose to be up to 2000 Hp pump .
How about loosening the gas cap to confirm if this is the problem, just a thought