I had a fellow named Wilco send me some dyno runs for his Cagiva Gran Canyon (fuel injected 900 motor) before and after a cylinder head replacement. Originally fitted with the same style heads as the later 90's M900 (W stamp) fitted with the 750 sized valves and 750 OR/VR cams, he had replaced them with some V stamp heads from a carburettor model 900SS running the OHT/VHT cams. The OHT/VHT grind is little smaller than the 900SSie cams that I fitted to a Gran Canyon with std heads some years ago. See http://www.bikeboy.org/grancanyon.html for more info.
As you can see, the bigger valves really help wake it up. It's the result I was hoping to see with the cams alone. Obviously the valves are more important. For a carby model M900 with the long manifolds the top end increase might not be so great, but even if it peaked at 7,000 rpm it is still a large increase.
Thanks to Wilco for supplying the info.
There's some more info in this youtube clip: