Thinking back, what made the 89s so fun on a track is that they had a 15+ HP gain in only 1000 RPM at the steepest part of their dyno curve. The bikes were nearly 50 HP at half max RPM, and they peaked over 60 HP (stock). 89 was the first year for the lowboy layout and those bikes actually turned really well once the forks were set up. They started worlds easier than the older CRs thanks to a small change above the exhaust ports. Funny thing was Pro Circuit did all of the cylinder work for Honda's CR500 National motors.
I have no doubt Rose's CR was a rocket.