Okay guy's, we've run a 305, have an engine sitting in our shop race ready right now. You DON"T have to buy all the light weight trick stuff. The key to the whole deal is the heads. You can only get so much air in and that is the limiting factor.
Because you can only get so much air in you're only going to turn less than 7000 RPM, with that you don't have to buy the 4340 crank and the speed parts that would be needed for a 410 class
It works if it is policed.
When our 305 class went away we went non wing racing with it and beat a lot of 410's on a dry slick track. I know all the Indianapolis guys are purist, but it really is an affordable way to race sprint cars (oxymoron)