Thread: Confusion on XPZ Head Combonation

Originally Posted by Boomer1919

Save your self the work of pulling the heads at that point and just run an xp cam.

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?

Originally Posted by Bio248

the XPZ can technically be run on stock heads, but wont make any power because it wont be able to flow like the cam needs.

but yes, i would run 130# springs with ported heads.

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