dont get alu roller rockers . as alu is soft the castings around the bearings have to be larger for strength, meaning a smaller beraing dompared to that os staninless ones. go to shop and look at the bearing size on alu and ss . also they dont do revolutions. they only move back and forth which is another reason to get as larger bearing as you can .
somethings you can get away with but i wouldnt on them. i also got hardened push rods . and rod guides .