question about stance and rake of a KZ550 ltd

I'm looking at getting an early 80's KZ550. I prefer the sport version, the KZ550A I believe it is. Not many of those around, but there seems to be plenty of LTD's, the version with the 16" rear tire and longer fork tubes.
My question is...is the steering head angle the same on both of these frames?
So if you put an 18" rear wheel on an LTD and dropped the forks would the stance and rake angle be the same as the sport model?
I know the frame varies a bit at the seat area, I don't mind that, but I'm a stickler for rake angle and love the tight angle of the GPz's.
I've seen a few pics online where people have dropped the forks on the LTD but they usually keep the 16" rear wheel, sometimes putting a taller tire on it, the stance seems to be pretty close to the sport.
I definitly want the 18" rear wheel with drum brake, and the 19" front wheel. I also assume an 18" rear wheel would fit without issue? swingarm is certainly the same, correct?
Any info or experience in this would be greatly appreciated.
thanks!

You might want to download a manual and have a look see. I did and it says the cruiser model has a steering head angle 1.5 degrees more raked out than the sporty version bikes. If you install an 18" wheel it will restore much of the difference but I'm not sure exactly how much.

At any rate, there are free factory manual downloads available if you look around. Very useful books.

I always pick the back end up a bit with longer shocks,

I'm well over 6ft tall, also I think they look nicer and importantly even on the GPz's you get a quicker steering response. I did the same on 750R and Lawson 1000R....and the GSX11.

The sport version being the 81 GPz550 D1 , that is the one to look for.