Don't worry this is a new motor build aswell... (look at sig) So in order to run the XPZ and 130's at a stock RR ratio the heads (wehter ported thrasher, s1, s2 or s3, ect need to have the valve guides shortened or milled?
Thanks, Bio... I'm just trying to figure out wether I need to have an additional work done with the heads in order to "be safe."
And Nick... well Brian's build is contagious