[Too Many Projects]

I would want backing plates also and nylock nuts WILL work loose. After I had a couple nylock nuts work loose from vibration on a trailer, I now only use all steel crimped locking nuts.

I bought a new 6x10 enclosed trailer to haul my Harley and had to place the rings in the floor and cut backing plates for them ..LOL The Harley and trolley might weigh 1,000 lbs, but under severe braking or a collision, it isn't going to rip loose from the floor.