The dutch twin shocks are totally different than putting a 30 year old air cooled 480 engine in an RZ (pain in the arse) or RA (easy) as they are single shock bikes coverted back and cannot be called EVO. An original twin shock chassis with a 30 year old air cooled engine, and conventional forks which had drum brakes originally (not converted 50mm Magnums) should IMO, be OK. The one bike which no-one objects to (here I go again) are those frickin HIDEOUS HL replica's which have nothing old on them except a fuel tank and engine, yet are evo legal. You can't buy a legit HL, so if you want one, (something I can't understand), you make one using all new the new shit you can get your hands on, and away you go with a pat on the back for doing a good job. You can't buy an RC450/500 but if you make one using a 30 year old chassis, engine & components, you get bagged for cheating. The rule legal way is to use a YZ465H or Husky 500 engine, but then you don't have your Honda. What's the difference between 30 year YZ465 and CR480 engines anyway? Nothing other than one of those bikes has a linkage in the rear suspension, I'm still at a loss at how that affects the engine. Personally I don't really care, or maybe I do, but the day the rules are eased up, is the day the numbers at the nationals will increase. Air cooled, non linkage, no disc brakes, should be that simple. Alas it's not.
K