I have done a search in the forums about this subject but havn't found anything on limits. I have a '69 with a freshly rebuilt .040 F, 38mm Weber, chevy distributor, header, new clutch and rebuilt 3 speed and new brakes. I was wondering if anybody knew what the towing capacity is of a factory '69 era. I am not so much worried about safety, I have read all the cautions on that and will turn back if I don't feel safe. But what can the truck handle? Will I fry the clutch? Will I ever get out of second? When I lived in CO I was always downshifting to get through the passes, but that was also before all of the mods. BTW the trailer is a 21ft, 5000 lb camper, with load leveling and sway bar.