TA performance Solid roller lifter. I have to drill a .010 hole in the body of each lifter to oil pressure will feed up into the rocker and valve stem. Teflon valve seals install into Champion R series heads SBC 2.02/1.60 valve 260lbs@1.90 install hight. Buick 455 pro magnum 5/16 tamper pushrods. I love the what this motor idle. no rattle from the valvetrain. the valve is lash at .0010. this is the best clearance for snappy throttle and no valve noise.