Can't answer the specific question on that model, but partial syncromesh applies to the top gears and is used to get up more speed while traveling. At lower speeds, you have to come to a complete stop to shift. If you find first too low for your needs,you have to stop and shift to second, then resume. Conversely, if second bogs down, you have to stop completely to shift to first, then go again. Not the best in marginal traction situations. While traveling if you find third to slow, you can shift to high without stopping. Full syncromesh allows shifting between all gears while traveling. Take note, I'm talking about transmission gears. Range gearing is usually never syncro. If you have 8 speeds - 4-speed, 2 ranges shifting between the speeds is either all or partial syncro, shifting between the ranges isn't. You always have to stop to shift between ranges.
Hope this helps
Pacesetter