My 04 2500HD has the tried and true 300hp/360lb ft LQ4 motor. I have read many articles where guys have swapped on L92 heads, new valve train, cam and lifters and an intake with a 4bbl carb. I am looking to make more power and torque while keeping EFI in tact. The way I see it, I have two basic choices. Option 1: Magnaflow Supercharger. This will add about 140hp to the tune of $6000. It is a bolt on kit with everything included. Option 2: L92 heads, valve train, cam, lifters, intake (L76?) and programmer. I'm figuring I can make the same power as the blower for half the money. Does anyone know which intake will work with the L92 heads? How much power can I make with the factory EFI? Is 500hp/450lb ft too much to expect? At what point will I need higher flow injectors and fuel pump? Ideas and comments welcome!