Never raced one that was stock (as I'm not stock wither), either mx or short drag.. I'd like to think that the 500 would win on the track (stock vs. stock), and the rappy would win on the straight-away. Furthermore, I'm precluding that you intended this question to be as if both riders were of equal skill, weight, and had similar launching techniques (for the drag).
By the way; Ask "flynbyu" what he thinks of a predator, it may be too graphic for some viewers! :grin_nod: