It's probably a 318 but might be a 360, check for under hood stickers for belt routing or spark plug gap and timing, vacuum hose routing, etc., they will tell you the engine size.
If a V-8 about 5000 pounds will be the maximum it will pull and that's at the bumper, a receiver hitch might get you another 1000 pounds.
Manual transmissions will pull better and last longer than an automatic.