So now my words get twisted into all 350s always beat 421's. Bhq at its finest here. Go back and read you illiterate bastards.
both stock chassis with extended swingarms. One was a out of the box 421 serval kit from "no limit", with all the goodies. Mine was a 350 "herrjugs port only" setup and built by me with all the same goodies.
So referring back to my original post. There will be "some" dune 350s out there that will mop you up. But that is less likely with a 421 cub. So as long as you really dont care about drag type racing get a serval.