[slotard]

Originally Posted by mattybilt79

Hitches are rated individually. Goosenecks are rated by vertical load and overall weight as fas as I know. Gooseneck balls are typically rated at 25 or 30k. As far as hitches for a 78 would have to go for manufacturer recommendations which usually don't go back that far. So it becomes a matter of what will fit from what others have. Chevy had trailering special packages but don't know if that was goose/5th wheel specific. C/K trucks had different ratings based on drive train due to weight differences and I'm sure having full time chain drive 203 t-cases might have reduced tow weights some to save part breakage. Same is true for new trucks there are different ratings for 2/4wd standard cab/crew cab etc. Chevy based tow ratings on drive train in the vehicle due to variables you have to know what your truck is equipped with, your truck is far from factory so only thing to go from is what its capabilities were from the factory. If you get busted pulling an overloaded trailer law enforcement goes off whatever they can find on or about the truck so if stock was 6500 pounds stay close to that and know that newer motor axles etc can handle it no problem.

A big part of why modern trucks have different ratings based on all that stuff is to keep GVWR/GCWR below thresholds that change emissions/registration/etc.