I am running a 235 with a 4:57 rear end. I now have the tac on the right setting and at 40 mph / 2000rpm, at 45 mph / 2200rpm, at 50 mph / 2500 and at 55 mph / 2800 rpm. I don't think I should push more than that because I don't feel I have much peddle left. Also what rpms should I run this engine at. From what I hear I can only change the third member to a 4:10. Do you know how much (mph)that will help me -- if I can find one. My tire size is 235/85R16. Thanks for all the help. I tell everyone about this site and just put my 48 chev panel in my first show and people loved it and I love driving it.
