RB and a roller Cam

You have to run iols that are formulated for the flat tappet stuff. They are "shelf" part numbers, but not stocked by normal retailers. Joe Gibbs and Valvoline Not For Street Use VR-1 are what I recommend when I use an aggressive flat tappet. While I don;t agree that 30yr old tech is the way to go, flat tappets definately are with proper care in assembly and break in.