Well without knowing more about the boat, I'd say a '53 GMC 3/4-ton will pull just about anything as long as you're not in a hurry.
The best source of information on GMC trucks of that era is
OldGMCTrucks.com. You'll find lots of info on the web site, plus a forum dedicated to GMC's.
Its a no BS kind of place with lots of good info.
I own several old GMC's and if I could find a nice '54 or '55 1st GMC COE I might ditch all my Chevs in favor of Jimmys. But lots of people already think I'm nuts.
