My Yokomo YZ-870C with a few mods + 5.5t keeps up ok I ran it at the state titles (NSW-Australia) the other week, only BQ'd but I don't think I would've done any better with my B44. Unfortunately the servo saver collar loosened itself off the bottom of the tube and jammed the steering in the final.. Next 2 vintage racer projects are a PB Maxima and SWB Cat.