my 6spd 01 ws.6 stock with no lid (factory ls6 intake) or anything put down 288rwhp and ran 13.0@108 if i can remem the mph correctly. at the time everyone called my car a factory freak. it later made 314rwhp with a horrid tune on a 95* hummid day with longtubes and a cat back running 12.7@112+(also not sure of exact mph). on the same dyno in the same shop my 6spd 00 ss, stock (with a slp lid and shitty intake) made 323rwhp, and i think its safe to say it runs like it. so power ratings are all over the board. my fathers ls1 vette made 330+, so it is what it is lol