It's been a while guys, but hello to the new forum look.
On the front forks:
The fork tube/pipe/stanchion is the same for all years at 37mm
Triple tree/yokes are the same
The fork spring (cushion in Honda terminology) is different but interchangable.
Bottom sliders (case): 78-79 are longer and have different (shorter) brake caliper bracket bolt spacing.
From that, obviously the caliper brackets are also different.
Internal damping rods are different but interchangable
The 78-79 has thinner stamped brake discs, so the calipers and pistons are also different.
78-79 front fender has slightly longer brackets to match the longer sliders and a different lower support bracket with a slight bend at the end of each arm for the same reason. Also has the speedo cable holder on the opposite side.
Front axle is the same, but spacers, nut and speedo drive are different. Speedo drive changed right to left on 78-79.
Axle clamps are the same all years.
Seals and dust covers are same all years.
I think that's all. Bet I've missed something!