Are you running a 6-71 or 8-71 or a 140. What pulleys or how much underdrive are you running? I heard the key is good btm end and don't over heat it. I have a heavy car (55 chev) so I need good power maybe 600. I had a 500 horse LT1 in a 57 and it was wicked not tubbed on leaf springs. Now my 55 is tubbed and on 4 lick coni set up so I think I'm ready to see what that will feel like! Thanks