I understand you can add extra pressure / volume with most aftermarket pumps and additional scavenging on dry sump systems as these HD's are, but most of these pumps were developed while HD was taking their sweet time figuring out how to make a oil pump work in the M8 platform. Also, these are full roller motors other than the cylinders themselves, and the bearings only need so much, also if you are already scavenging all the leftover oil, well then.... Hey, I'm probably not the one to preach here though because I've spent so much unnecessary money personally building many type of engines over the years but I guess I'm finally starting to realize in my moonlight years that I could have saved alot of money along the way. The peace of mind I created by over building / spending seems so unnecessary now. My favorite new saying is "Just because you can doesn't mean you should"