U.S Car Tool sub frame connectors install

They look great. I'm still confused on hows the best way to install them, on the wheels or on rotis' or other.
Definitely the rotisserie, I flipped the car on its roof, got on a mik crate or two and used a 50lb piece of steel to hold it down, made the slight modifications and tack welded them in place, once that was complete, rolled the car sideways to get a good weld angle and went to town very staight forward and pretty easy. good luck and hope this helps