Like i said though thats just what the guy told me, but the 600 ho makes 120 hp out of the crate and is supposed to take a stock 700 no problem thats without the twin pipes. So one would think that that the 660 kit alone should in fact make some where at least in the 140 and up range with the twin pipes, and the 725 kit should make somewhere on the upperside of 150+ maybe more. And your right the numbers on the Slp sight are for the 110hp 600 the new 600 pipes havent been relased yet, but be sure that I will be getting a set as soon as they come out, and i will be posting my input and some numbers for you. The 600 motor even bone stock sounds like its going to be a screamer anyhow.