The OEM's went to rollers to be able to meet the EPA standards ( and a good portion of that was to cut friction losses ), not for performance reasons. Street grind flat tappet cams can easily duplicate roller performance with a lot less valve train stress - and BTW, those high load valve springs needed with rollers affect valve train longivity at ALL rpm's - all the time. That equates to not only higher initial valve train $, but higher $ throughout the entire life of the valve train( and only the valve train if you are lucky ). The point I have been trying to make here is not that rollers are a bad thing, but that they are mismarketed by many cam manufacturers ( for obvious reasons - $$$ ) and sold to the ( to be kind ) less knowledgeable as a major performance gain when in most street and mild performance appications they are not. JMO. My suggestion is that before you pop for a roller cam, take a good look at your particular application. Don't just jump in to a roller because " all performance engines gotta have one".