I think the 305s would be fine. But I'd still get the 315s cnc since your 509 might grow balls some day and become a 565 and the 315s cnc would be ready to bolt on and go. Long term buy the 315s. IMO
Wheres all the true dragracers gone. Isn't racing 1/8 racing kinda like kissing your sister. 1380 all the way!!!!!!!!!!!!!!!!