Like everything, depends on what you'd want to spend. Lots of solid rollers on the street - not cheap, figure at least $750 up for pressure fed units. As Brent said, if the block can't feed it - that's a real issue on a street car. Nothing wrong with hydro rollers either. I've "lost" my last flat tappet, I'll sit before I buy another for any performance application. "Oh, but flat tappet is cheaper" - well - one solid flat Crane about $240, $140 for a set of good lifters. Spend that twice because of a failed break in and you've overpaid for a set of hydraulic rollers. That can be reused if you pick another cam, by the way.