Curious to know why do you want change cams? Do you feel that you maxed out the xp? Probably not .. I would stick with your setup plus the xp cam idles wayy better then the xpz... And since you really dont want to do porting for heads.. You should stick with it ... Goin bigger isnt always better... Be surprised how much power you would make with that cam And surprised what those cams wouldnt make at the dyno..lol