I have a 2000 Chevy K 3500 dually with a 7.4L. I'm looking for more lower RPM horse power, I tow and haul with it AND it is my daily driver. I also like the rumble idle but I want it to still run on pump gas. I am planning on rebuilding the engine and boring it .030 over to true up the cylinders, run long tube headers with 3" exhaust to the cats then 3 1/2" out the back, and add a true cold air intake system. I would like to gain maybe 200-300 more horses. What else can I do?

 

higher axle gear ratio.

 

I was thinking about a bigger cam just don't know what size to get