I believe the '83 has the same speedo sensor as the 1200s. If your speedometer cable lower end has a tab for a screw to hold it to the sensor rather than a groove around it the 1200 type should work. There should be someone who currently has an '83 rather than working from memory as I am come along soon to verify.
I would stick with stock nylon cut gears. They will never be as noisy, they do not retain heat. Mine is a 92 and still uses the nylon cut gears. Like anything they should be serviced. This gear at least everytime you change your tire.
id go for it from bike bandit myself. I dont see any differance on the exterior or where it goes into the wheel between a 83 and 84., <the ones i have here>like I mentioned there might be a tooth count differance but maybe not. cant you swap the 82 drive gear into the 83 or is there a differance.JB