The main reason I went with a solid flat tappet on my car is that since its a street car and see's alot of miles I did not want to pull my roller lifters every few years and have them rebuilt because I would have wanted a solid roller with a good bit of spring pressure. So I went solid flat tappet and broke it in right as its been in the eng since 2011 with no problems. I just did not want to worry about my roller lifters since I know I would want to check them every few years at least. If mine was a race car I would have went roller for sure. Ron