From the factory, the 1979 - 1985 trucks had solid front axles, and the 1984-1985 4-runners.
All of the SFA toy axles are the same dimension, 56" WMS to WMS. '8 inch' ring and pinion (7.8" actually), 1.3125" 30 spline axles, 27 spline birfield outers, Aisin locking hubs (very strong).
The axles are all stamped/welded steel, leaf spring with SOA configuration. The basic housing was the same throughout, however, through the years, additional gusseting/bracing was added to the long drivers side tube. The 1985 axles are the most highly sought after due to the full-length gusset. (I have 2 of these, and an '83).
All have disc brakes with a solid rotor. Land cruiser vented rotors can be swapped on with the use of later IFS calipers.
The early 1st gen pickups have round headlights, this would be the 1979-80 models. The 81-83 first gens, like mine, had rectangular headlights.
All later toyota trucks use rectangular, as did all 4 runners, since they were based on the trucks.
Whats with the interest in Toyota parts?