Don't waste your money on cheap rockers, especially roller tipped. If you're going to do it, buy a good quality full roller rocker. The valve tip is not where the must friction occurs, the pivot ball is, so you're leaving a lot on the table with just a roller tip. further more with a cheap roller rock er, when it fails, where are all of those little rollers going to go? Into your engine...which will cost you a lot.