Those heads need a 2.08 intake valve because of the already large throat set by the cnc porting. I just did a set for an engine we're building, with our valve job, chamber touchup, 2.08 intake valve, ours go 277cfm at .500 and 290cfm at .600 lift. They are a bit unstable after .600 lift but only dropped a couple of cfm...untouched ports other than the valve job, tootsie rolled the short turn (there is a sharp edge on top of it that needs knocked down) and chamber unshrouding.
