I figured since my car was a street car and I am not out to set a world record I would use the solid flat tappet. One reason is that its a cheaper setup and cash is always needed around me. And the second reason is I dont want to pull the lifters every few years to check them. I have heard of roller lifters loosing a needle bearing and wasting an eng. Now I know many guys do run them but I figured I would want a nice one and it would need good spring pressure. Who knows I could have run a roller and got away with it for many years but I would feel better pulling the lifters every few years and check them for piece of mind since I put a good amount of miles on my car each year. Like Dwayne Porter told me that valve float is bad with roller cams so you need to run much more spring pressure with a nice size roller you plan to race some. Valve float can let the cam hammer the lifter some which is tuff on the roller needles. So you do want to be sure you run the proper spring pressure with the roller. Yes it will make some more power but I have no complaints with my flat tappet cam. And I am not trash talking rollers as tons of people run them and do fine but I just would not want to be the guy that has a roller lifter come apart because I did not pull and check them every few years. Good luck which ever you choose. Ron