Not sure any of this will be of any help or not. Here are some things I have found in the past regarding 650/750 cams,values and head info. Take all of this with a grain of salt as I am not claiming the data is true, rather I found it somewhere on line in the past.
valve size same till F2
intake 33 mm or 1.299 inches
exhaust 28 mm or 1.102 inches
F2
intake 34
exhaust 30
the 750s are the same as the F2
all models other than F2 are the same -
intake open 22 BTDC
intake close 52 ABDC
intake duration 254
exhaust open 60 BBDC
exhaust close 20 ATDC
exhaust duration 260
F2 differences
exhaust close 22 ATDC
exhaust duration 262
F3 goes back to other settings?
bore and stroke
62 X 54 mm or 2.441 x 2.126 inches
head volume #s are
77-80 23.7
81 23.3 to 24.1 or average of 23.7 same as early one
82 24.8
Interesting Facts, Re Head swapping z750 heads/cams/stuff
Valves are bigger in the 750 head.
z650 head 32/27 (in/ex)
z750 head 33/29
As are the intake runners, but I don't have the 650 head to measure currently, but definately by a couple mm (3-4 off hand, I measured once)
Combustion chamber volume is similar enough to be irrelevent. (esp if machined)
650 23.3-24.1cc
750H 24.8 +-0.4cc
750L 25.3
Gpz750 25.9
Turbo 24.6
Cam heights. (in mm)
z650 35.73-35.87 (both)
z750 36.245-36.353 (both) So 0.5 more lift!
gpz750 36.746-36.854 (in) (So 0.5mm more again)
35.746-35.854 (ex) similar to 650, but longer duration. 286 vs 260 (Or 262 on the F models)
Turbos have 650 cams.
Also BEWARE, SOME camshafts/head have a different base circle diameter most are 1.100" some are 1.070, rare ones are 0.900!
z650s have a differnet 5th gear ratio than 750s. 24/27 (750 21/24) Discovered this one long ago. Turbos are completely different.
early z750s (E/H) ran Keihin CV34 carbs.. later ones and Gpz ran Mikunis BS34. I had a set of Keihins for years- Excellent carbs (Have 2 sets spare)
One reason is the Keihins run a Primary and Secondary Main Jets. Mikunis have One.
KZ700s ran a 64mm piston. (66 for 750, 62 for 650) Sounds like a suitable alternative to a Wiseco kit. Same size...
Turbos have a 16mm Gudgen pin (wrist pin), instead of 15mm. And flat top pistons.
Early GT750s have a little hole in the conrod, that squirts oil under the pistons, and onto the cylinder wall.
Thats enough for now.
Sean