The D-1 all the way. Its capable of 32 lbs of boost, sounds mean, and has a longer warranty than a Vortech. The D1-SC is self contained so install would be a breeze, and anyone who thinks a self contained D-1wouldnt make power is insane. I ran a D-1 on my 342 and at just 4900 rpms and 12 lbs of boost it put 514 to the wheels with box stock trickflow TW's and an alphabet X cam. If I had a custom cam, AFR 185s, and could rev to 6500, 650 plus at the wheels easy!!!! Trust, you dont need a bigger blower than a D-1. Procharger is the sweet!