SC motors run with 21.5 fairly well, running SC only is a recipe for disaster, and tech issues.
Even a proper $50 cheater SC motor is no faster than a 21.5 BL for 10 min races.
Just beware, there are SC motors out there, that have less turns, and quite different specs, but look very similar to the Kit Tamiya motor.
I've heard recently, that a 20 yr old fibreglass kit F-103 beat $500+ dollar F1 cars at a UF1 race in the "Open" class
As long as you have a spec motor (preferably 21.5) and rubber tires, the high end cars have nothing extra to offer, other than bling.
batteries shaped like this will fit with no issues.
2400mah will run 10 mins easy.
