As I stated I run a solid flat tappet in my street car. But that said there are many who run solid rollers in street cars. Myself the kind of roller cam I wanted to run called for a lot of spring pressure and I did not want to worry about changing springs more often or worry about a roller lifter coming apart. I have heard you should pull solid roller lifters out of the eng every 3000 to 5000 miles and check them and replace or rebuild if needed. I don't know if most guys running solid rollers do this. I was also told that if you don't run enough spring pressure with a solid roller you could run into valve float which is a no no as that can hurt a roller lifter as it may hammer some in valve float which is not good for the roller bearing. So I went with a solid flat tappet and I am very happy with it as its been 8 years now in my car and it still runs the same 10.70's and 10.80's driven to the track. But as I said many people do run solid rollers on the street and I would be curious as to how often they check the roller lifters since I know a few of my friends have run solid rollers in street cars ? Ron