235
Let me correct some incorrect posts
1 ROAR has not dropped 235 4wd and has opened the class to include unlimited 200mm with open body rules
2 You do not need a big block 15 to compete and there are some very competitive smallblocks available
3 There are still new 15 big blocks available.
4 You can buy new mugen avance and serpent 835 Serpent also makes smallblock mts for their car
5 Tires are still easily available and much cheaper than 1/8 even if you don't take into account the much better tire wear on a 235.
6 They are much cheaper to run and almost as fast as a 1/8. Drivetrain requires much less maintenance than a 1/8 as the loading is much less.
7They are very similar to drive as a 1/8 only better balanced and not as throttle sensitive {read that as easier}