They are functionally different in 2 places that I know of..
1. The fan speed switch of one of them (GMC I think, but it has probably been 25+ years since I was in there) has a step in the lever while the other fan switch does not.
2. One of the GMC vertically moving levers (again, I can't remember which one) moves the cable in the opposite direction of the Chevy.
'57 GMC 102, Original 347 V8, HydraMatic, 3.08 rear gear, added A/C, disk front brakes, HEI, AFB carb, '98 Honda Black Currant paint. T-boned and totaled 10/12
'52 GMC 152 Stake Bed, Original 228, SM420, added A/C, HEI, disk front brakes, '67 Chev 3.55 rear gear. Gets used as a real truck.
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