I had spoken to Rybo offline in some detail about the 600 spec racing idea as well, and now that I understand where his head is (narc'd up, but that's beside the point) and we talked through a couple theories, I think it could work.

If there's money on the line, fast guys will show up on new(er) bikes that qualify for it. This makes sense, even in a class designed to limit the impact of one's fat wallet. I know I certainly would do that if it were legal and I thought I'd be in the contingency-level positions.

That said, it does somewhat of a disservice to people who want to go race an older bike, as they will have a performance disadvantage in multiple areas. So I like the idea that a vintage-legal bike would be allowed to race under SB motor rules or something related to it (still within the 'spec tire type' rules, which will be a great equalizer for corner speeds). This would allow these older disadvantaged machines to run on par with newer bikes and not get walked on the straights. It would also let people that (a) either already have these older bikes or (b) can build one for less money than a newish one would cost (stop laughing) race the class, and have 'spec' mean something. There's also nothing preventing someone from gridding up an old 600 with a stock motor and racing on the cheap.

Unless we limit it to one specific bike or a small subset known to be performance equals, the bike part of it is hard to make true 'spec'. But if we think of spec as a performance definition rather than a manufacturing doctrine, it would make for some damn interesting racing.