i have a 03 silverado with a 4.8. i was wandering what exhaust system to go with. im planning on getting a custom next week. right now i have short tube headers and a one in two out magnaflow straight through muffler. i was wandering if i cut off my cats and got the tune for this, how much would it help? and do i need to be running true duel exhaust?

 

imo you don't need true duals w/ a 4.8. i think the best exhaust set up would be a single 3" in and out, thats what i have btw w/ my 4.8. if you had a 6.0 or higher i think true duals would be good. i've heard people claim their top end is much improved with takin' off the cats, it would be louder though.