Thanks for the heads up. Yes, the lifter bores are cross-drilled with a fairly large gallery running through all twelve bores front to back. So I have a hydraulic block, and a composite cam gear which lead me to conclude that I need order hydraulic lifters. I did some basic online research and apprised myself of tech concepts like "lash ramp" on camshafts! If by some freak chance the cam I've got is for solid lifters (despite having the composite gear on it) will there be a problem mating hydraulic lifters to it? Will the lash ramp disrupt driving performance?