Wanted to install a receiver hitch on the 78 k20, ordered one after rep gave me suggested part number for a Draw-tite #41947. well the tails of the side brackets towards the front of the box were too low and hit the new exhaust on the truck. Not wanting to cut that up I opted to send it back to the tune of $30. Has anyone recently installed one that would have a manufacturer and part number that would work. the one I sent back was a class 5, thinking I could get by with a 3 or 4 whatever fits. Any help would be appreciated