Thank you sir.
I don't know why I missed it, but the same paragraph is in the 1951 GMC Maintenance Manual.
Given that the is no spec for minimum thickness, the only thing to worry about is was there material ground off in the past.
'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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