As said above height is the problem, I have put a gsx1100f motor (1127cc) in a gs550 frame about 12 years ago, I chopped out the bottom/side frame cradle on the right hand side and made in as a bolt in part so then you can make a bit more room for the motor.
Had to use a 16t front sprocket instead of the standard 15t to get more travel around the swing arm mounts (just because I had broped the motor as low as poss to get to can cover).
I at the time I used the gsx1100f power screen running gear so did not have much a problem with chain run, but if you're putting any bigger rear wheel than a 4.5" rim you will need to do some work around the swing arm mounts.
Using a 750/850/1000 frame not as much a problem but as the 550 frames are smaller length wheel base etc they are much more fun to ride when done.