Since it is so clean now would be a good time to put some heat shield on the bottom of that, it will reduce heat & sound , it's self stick, has semi rigid metalic surface and is flexible so it will conform nicely to that piece. I think wngrog...
Shackle bushings worn, loose will cause this. I'm guessing your shackles are straight up & down ? What deg do get when you put angle finder across upper trunion studs with truck sitting level ?
It definitely cheaper, I miss the big trees at the good spot just across river, that was the sweetest spot when the trees were still there, I think they went in 05 ish, its just too sunny to camp there anymore, it's funny as much as that place...
My best guess at the old pattern measures without actually measuring or looking it up, I should have clarified or refered to the older/smaller, not square pattern using 10mm studs. I am sorry for any confusion or misstatement.