Grigg,
According to the
1955-2nd Chevrolet Truck Shop Manual, Jerry seems to be correct. The 3/4 and 1-ton prop-shaft brakes are different in comparison to the 1.5 and 2-ton prop-shaft brakes.
A GMC 150 is a 3/4 ton truck. I would suppose (guess?) that 3/4 ton Blue Chip GMC and Task Force Chevrolet trucks are similar with respect to the prop-shaft brake set-up?
