Yes and yes, i have the GSXR1100J {last of the early GSXR's1988} swingarm on my "F" build and it was a straight slip in fit....I had the mono shock section removed and twin shock mounts welded on, the 1100 swinger came out about 45mm {under 2 inches longer on the 750F so it would be only half an inch or so longer than the 550.....The 750 arm could be slightly shorter when cut down....You will have to make up spacers for your wheel but thats not too hard....
Mick