What's this Long Horn capable of hauling?

[Ken B]

So, I'm thinking of picking up a vintage in bed camper and or a vintage travel trailer. I have no idea what my truck was rated to tow or how heavy of a camper I can put in the bed. My truck is a 1970 C30 Longhorn with a healthy 350 with a 4 speed and 4.10 gears. The truck is all original with only 86,000 miles on it. Runs and rides like new. It has the leaf spring rear suspension with aux. helper. Can anyone tell me what diff. is in my truck? Thanks for any help.