Aaron, I agree 100% with John Z. If you are going to do much driving, you will find that the "140" cam and crossram is "all show and no go". This set-up has no vacuum, no power under 4000 rpm and will be constantly in need of tuning. The stock exhaust manifolds will only make the problem worse. I have two Zs with the "140" cam and cross-ram, but both have headers and non-restrictive exhaust systems. In addition, they both have "K-66" ignition. Both cars are very tempermental, hard to start, won't idle under 1200, and would probably be outrun on the street by a good-running single four barrel car with a 30-30 cam and stock exhaust. But they sure look and sound cool! These cars are rarely driven, so I wouldn't consider putting them back stock. My two cents. Tex Timberlake