Unless you're going to the moon, the stock oil pump works great. Justchamfer the oil-filter return passage and any other accessible junctionsto remove sharp edges and promote oil flow. High-volume pumps tend tooverload the small drive gear, leading to total oil-pressure loss. We'vebeen there and it's not pretty. Now we only use blueprinted stock pumpsin sub-5,500 rpm applications like this. For extra peace of mind, Dutraoffers a special heat-treated pump drive gear at www.slantsix.org.