Originally Posted by awoodman
Will I even have any more power if I keep the old hydraulic roller lifters with a performance cam, versus buy a kit with a new cam, and hydraulic flat tappet lifters? I imagine that a new kit would be more wise, because my engine had 158000 miles on it, although the lifters are fine...
Roller lifters, in and of themselves, will give you almost no hp gain, all things considered. Where they really pay off is on very agressive cam profiles. They allow much faster openings and closings. The lobe on an agressive roller cam is almost a rectangle! LOL A flat tappet lifter will end up scraping the edges of the lifter on the cam lobe if you tried to use it on an agressive roller camshaft.
If you are going to re-use your old roller lifters, you MUST run them on a roller cam.