First, you have to seperate hydraulic rollers from solid rollers. Solid rollers need more prep to be safely run on the street. Hydarulic rollers are simply a hydraulic lifter with a wheel on the bottom. They are heavier, and while they rewuire no real modifications, IMO, they are not worth the money. Because they can't have a rate of lift as fast as a .904 sized solid flat tappet. So you've got a larger price tag, need a heavier valve spring, and can't move the valve any faster or better than a flat tappet. The only reason IMO to run one, is to steer clear of needing to run the high zink oils or additives and avoid the breakin procedures. If you want a solid roller on the street, again, IMO, the block needs lifter bore bushings, and the cam needs to be carefully chosen bearing in mind idle time, valve spring life, and roller lifter life.
