Matt's 2005 GTO

Im sure he knows he has to flycut his pistons and if u look up the cam on comps website it even says its good on any
LS/R Rectangular Port 3-Bolt Cams (For All Out Power Only, 5.7L - 6.2L). So why would it suck in a smal cube motor if comp says it recomended in any 5.7 to 6.2?