What is the engine serial number that is pressed into the block to the rear of where the distributor goes into the block?
Is there an ID plate on the driver's side door jamb (what code is on it)?

That looks like a relatively short bed (and, relatively short wheel base). My guess would be 1/2 ton short bed.

However, I cannot clearly see the wheels, but, if they are 8 bolt, twotone is most likely correct.
How many wheel bolts on each wheel?