Good morning Rocket Man,
here's a Super Chevy article that documents the performance gains from headers and other easily accomplished mods:
http://www.superchevy.com/how-to/en...sting-new-mods-for-the-lt1-motor-part-2/One of my sons has that same motor in his daily driver pickup and he found a nice performance bump from a mild camshaft from Competition Cams and it still passes a California smog check no sweat.
He also has a resto-mod '66 Chevy PU and I made him this exhaust system for it. The "H" pipe makes the engine practically silent at low throttle openings. He likes the "Eye candy" benefit of the headers too. Another "Eye candy" upgrade is engine turning some of the metal panels if you're willing to learn a tedious skill. Here are a couple of examples of engine turning on my roadster.
Have fun!
Ray W
