The two most common mistakes street engine builders make is "Too much cam" and "Too much carburetor". Any cam with an "advertised" duration of more than 260 or so will probably produce low manifold vacuum, a lumpy idle, and less low end and midrange torque than a "stock" cam. I've proved that on the dyno more times than I can count. Where those long duration/high lift cams shine is at RPM ranges few street engines ever see. About the hottest cam I would recommend for the engines my high school students wanted to build was a Comp Cams 268H. Along with a fairly low rear end gear, and a slightly higher than stock stall speed torque converter, some of my kids became kings of the neighborhood stoplight drag race scene- - - -and they had the speeding tickets to prove it!
Jerry
