the Bendix unit was a hydrovac, never seen one on a 1/2T ... power steering was offered from at least 55 on Chevys, maybe earlier - it's RPO 350, called "hydraulic steering", RPO 351 for bigger trucks, but still used the same generator mounted pump .... can't imagine GM designed a whole different setup for GMCs, they didn't do that kinda thing, used what already was at hand
never seen a 50's light truck with a rag joint either - any kit available for power steering
invloves installing one tho - have you checked over at the
old GMC.com forum? those are the guys who'll know
Bill
checked the assy manual - seems they did offer the hydrovac on the 3xxx series, V8 equipped only, mounted beside the engine on pass side, woulda been really rare considering the V8 wasn't common