Don't know or see anything on Valco boats, I had a 12' Sea King with a capacity of 565lbs. Higher capacity would possibly have 20" transom, deeper side walls and wider beam.
From what i read up the USCG Method used, is to take the length multiply it by the width, divide that by 15... that will give you person capacity: 12'X5'=60 divided by 15=(4) person or 600 lbs at the 150lb per person standard.
Just remember to take off the weight of the engine, fuel tank, and gear from the carrying capacity before you figure out how many people it is safe for. If it's 600 you are really only looking at three typical adults, at most.
