I'm currently in the process of getting my street MC21 R ready to race in a 250 series we've got here in aus. Its basically a produciton series, limited in what can be done to the bike, needs stock ignition, suspension, chambers etc. I've been given allowance to keep the delimiting (which is already done) so that it's a more even playing field, 250 strokers (especially cheap ones) are hard to come by down here. No gp bikes/engines, and no HRC style parts

There's a couple of questions i'd like help with to get my old baby going as fast as the aprilia RS250s (i'll be the only jap 250, trying to convince a few other nsr/rgv owners to come along!):

As said above, i have an R model. Is it worth trying to buy some SE/SP adjustable suspension. or just get what i have professionally sorted (needs to be from an NSR MC21). Can i just use SE/SP caps in my R forks to make them adjustable?

Same question re engine, is it worth trying to source an SE/SP dry clutch engine? Is there any differences in ratios etc?? The cheapest i've been quoted is $2000 AUS (approx £800) which isn't much lest than i paid for the whole bike!

Finally, i'm currently running with no airbox, just 2 pod filters (jetted to suit). Am i better to get an airbox/filter and do the intake hole mods? I guess i'd need some dyno time to get it re-jetted

a basic overview of the rules: http://www.mrrda.com/2007-250-production-rules.php

All and any advice is much welcome, especially if it's not going to cost me much!!