I have a 2005 2500hd duramax. I have ppe, afe intake, afe mouthpiece, 4" exhaust, etc. I constantly have people telling me my truck is slow. I know my truck is fast. I ran a mid 13 on ppe's quarter mile. I told people that tell me my truck is slow to line up an average corvette and I'll smoke him. I'm not afraid to race anybody, but I don't want to lose.. I can run efi or higher tunes but I would need a transmission. I have the money for a stage 5, but I want to know whether I want it. I need it to run better tunes, but is that necessary to beat an average corvette???