7 1/4 or 8 1/4 Highway gears

You can always just measure them without opening anything. Fix one wheel on the ground and don't let it move. Turn the other wheel 20 times and count the number of turns on the pinion. The ratio is #pinion/10. There is an extra factor of 2 because you are holding one end stationary. This only works for open rears. On a sure grip, both wheels would turn the same amount and the ratio would be #pinion/20.

But I need the entire rear end, not just the carrier or just the gears.