Did just this. A Howard's "retro fit roller",in a Magnum block. The cam comes with a cast iron gear,for the intermediate drive /oil pump shaft. Used stock lifters,I would suggest, researching a longer pushrod possibly. Until you inform more about your build,can't say more.I chose the Howard's because of the cast iron gear,the cam specs,& customer service. Watch Comp,sometimes you have to ask for a cast iron gear. My .02....