stage 1,2,3 27. fuck knows what that shit means.
there is almost 10 degrees difference in exhaust port timings between the cheetah and serval, and almost 5 degrees in transfer timing.
if you port the serval to those specs it becomes a cheetah cub, or ported in between you loss more of one and become more the other.
you can port the serval to have more top and lose very little bottom and be a fun cylinder, but thats an expensive cylinder by the time youre done with it.
to know how those "stage 2" ported servals will perform, you have to know port timings,
i like serval based cylinders coz, if youre not sure where you wanna go, you can always port it into a cheetah cub, tho its an expensive way to go.
if youre always in upper gears and wot most of the time, buy a cheetah cub.