I would think ultra street would be the closest thing to a working mans radial class. The record for that class is in the 4.60's I think. But that's the bad boys running that. I would think a low 5 sec car would be competitive a lot of the time except for the huge events. And at races where they don't have a ultra street class they seem to offer the ultra setups a huge weight break to try to run with the x275 cars.
