I bought the rectangular style stock replacement filters from k & n and fram airhog for mine. The same filter works on the 5.3 and 6.0 . About $69.00 if i remember right. The k & n cold air intake kit runs about $350. One important note on the k & n filters. My buddy installed the cold air intake on his GTO 6.o LS2. About 3 weeks later he started getting a check engine lite. Took it to the dealer and they found that the excessive oil in the k & n filter had sucked up onto the mass air flow sensor and caused it to produce the faulty readings. They wiped out his air intake tube and his sensor and charged him $60 to diagnose it. If anyone plans on installing the kit, be sure to wipe off all the excessive oil from the filter before install.
Ron
