Hi, I just had my Quadrajet(7028240) rebuilt for my 1968 Buick Wildcat. I'm at the 'Dialing" in stage after re-installing it and was wondering what the best idle rpm in drive would be for best stock performance. The manual states 550 rpm when in drive for best emissions. My engine has mild upgrades like stock big port heads, upgraded ignition, 3" x-pipe with dual 2.5" exhaust for better flow. Stock transmission. ignition advanced to about 34* of mechanical timing. Any suggestions?