My local Airhead mechanic thinks I would be better off with the original displacement. He feels the 1000cc kits result in additional vibration.
The new kits are very well balanced...when I got my 1000cc kit I weighed each component. I found that the wrist pins and pistons and the were exactly the same weight. The cylinders were 0.1 oz difference but that doesn't contributed to vibration. The only thing I didn't weigh were the conrods...I decided not to remove them. So, I'd be hard pressed to figure out how this new kit would result in additional vibration.