I'm sure you've all seen the uniball aka one link suspensions with trailer balls and grader balls. I have a little project that i want to use about 12 trailer couplers. I don't want to use grader balls because they're to expensive and harder to source if one breaks. Also it has to be a ball mount(no 5th wheel) I'm trying to determine what the "lift off" (negative tongue weight) rating is on the various styles. It seems like they'd make one where the ball slides up and then forward but all that i've seen are ones that just lift almost straight off. They don't seem to advertise this rating, but i know some of you have loaded some heavy a** tractors or jacked up a trailer with a whole lot of weight in the bed with the jack under the trailer. Also i'd like to know which ones have the most side to side roll clearance. Any good gooseneck designs fit the bill? btw www.redneck-trailer.com is where i get my trailer parts from and i'm pretty happy with them.

This didn't answer my question, but its a interesting article about what standards are in place for couplers: