Thats a 1/2 ton,Will. Those extra rear springs are overloads,or "helpers". If it was a 3/4 ton, you would have 8 lug wheels,a longer bed,3600 emblems on the side of the hood, and other differences. Dont sweat the 3 or 4 speed,it was just ordered that way.
Pretty nice lookin truck,youve got a good start.
Marty