US CAR TOOL Frame Connector Questions

I see some have welded these on while the car is on a rotisserie. Has anyone had issues and if the car is currently on a rotisserie how can I make sure the doors will shut? I can't take it off but with the whole bottom clean I would like to install these.

I installed mine on the rotisserie and reinforced the door opening, my rotisserie came with bolt in door bar reinforcements but you could tack weld some 1" square tubing also. Everything fit like a glove during assembly.