I have 03 Silverado 4.8 I have most bolt ons kooks LTs and Ory into a single Borland cat back underdrive kit, cai, e-fans, corvette servos, 4.56 posi rear end and a wheatly tune. I now want to make the next bump up to 400hp (crank) is it possible what's the best economical combo for street that will still allow me to tow? Will I need a stall im assuming a cam and head package to get what I want, so port stockers? Any suggestions helpful

 

Heads and a camshaft will give you a solid 50-60 hp bolt on. I will look into a small converter, a head and cam set up that would add TQ more then HP. Something on a tight LSA, mild split on the intake and exhaust duration.