i bet the c20 would have no problems with pulling the boat. but you'll have to leave the rear alone. to keep the pulling power you want it to be low geared and if you try to change it out for some highway gear it prob won't be up to the task. if you want a highway truck maybe you should look into a c10 ot upgrade. it is going to take a lot of time and $$$$ to change the front end out or switch over to something modern with the disc brakes. i pull and haul more than that with my 64 c20, but i also roll down the road at 50 mph. if somebody sees it with 6 lug wheels and disc brakes they may try to rip it c20 badge off in discust. hahaha, just kidding on the last part. hr