Sure, I just put a V-Max rear end in my 83. I seriously doubt I will see any gas mileage improvement for awhile as I can't seem to get past the throttle giggles. I do not expect the gas mileage to get any worse for me in my 2up riding around the mountains and I routinely get about 45 mpg. Now, if I am going to make a 75 mph run down the interstate, I may see a little drop.
The reason I went with the V-Max rear is I have another 1200 engine that I installed an 02 Venture transmission that the gears are wider spaced. This way, 5th will be about 5% higher, but 1st will be about 10% lower.
I just need to get my butt in gear and get the engine swapped out.
To use the V-Max rear I had, I had to go to an MKII driveshaft and a different dust cover/shield on the wheel. Other than that, it was a straight swap.
RandyA