It looks to me like there is an open U-Joint at the back of the transmission. If that is the case, it is not a 1/2Ton setup. The 3/4 Ton has a short driveshaft behind the transmission, carrier bearing and then a closed driveshaft to the rearend. What does your truck have?
I’ll look tomorrow. However- if both the engine and transmission were swapped from a 3/4 ton wouldn’t it make sense if it has the set up you described?
Plus, there are the other items that point towards 1/2 ton: wheelbase, number of leaf springs etc.
