Ls1 ls6 which one?

Which one would be the most beneficial as in power out of the box as in just a stock pull out? Im talking 98 up Ls1 and 00 up ls6 even though I think the ls6's went up in power every year?

Also what would the mpg difference be between a 6.0l and a 5.7l? Thanks

Well I think in 01 GM used lots of the LS6 blocks in the F-bods. The full LS6 motor would be superior due to the better cylinder heads. 98 motors has larger injectors. 98-00 F-bod motors had more lift on the cams. 01-02 motors had tigher LSA. Vette motors are similar.

I'd at least toss in a mild cam if you have the motor in the garage/on a stand.

MPG would be similar if both tuned up equally via EDIT. 6.0 has a larger bore and can support larger intake valves. Most are the low comp variety LQ4 but a high comp LQ9 is a good choice!