If Howards grinds their roller cams on Billet blanks, I would go with their recommendation. My hydraulic roller came from Bullet Cams and was ground on a new cast iron Magnum blank, so I can run a stock intermediate shaft. With a billet blank, you will either need one harder than Chinese arithmetic, or a bronze one that will wear faster than the cam. Good luck to you. Any of that stuff is hard to get right now. I tried to buy a Lunati Hydraulic roller, and the Lunati guy laughed...and said they didn't even have cam blanks to hit each other in the head with if they got in a fight in the shop! This was a little over a year ago, but it ain't changed much.
