Seeing your 2 latest postings, you must have a vengeance going with some 5.3L buddy of yours or something! I know you mentioned that you're looking at new trucks 4.8 vs 5.3 and comparing, and I really think that the $1500-$2000 dollar difference for 10HP and 20-30 ft-lbs is not worth it. IMO. Based on the other posting, upgrading exhaust and filter all ready has you close to if not equal to a 5.3L and the nelson tune should get you by a 5.3L with no problem.
A forum community dedicated to GMC and Chevy full size owners and enthusiasts. Come join the discussion about Silverados, Sierras, and other full size trucks performance, modifications, suspension, lift kits, tires, maintenance, and more!