In my "Hand Drawn" picture (1st post, 3rd pic) for the 38 Belt moldings drawing is it true for "that year" truck one thin and one slightly larger or is all three truck years 36,37,38 have the same size two belt line moldings.?

Thanks for all the input for what fits what but all I wish is to Identify that trucks year, Chevy or GMC no big deal as both are made by GM. It would be great if I had it but I don't. No paper work or VIN numbers to trace it down just the picture with his Company Logo on the door.

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