Gus,

I put a brace in my vert in a square across door jam and across interior (across front of rear seat area and under the dashboard. I also anchored one side to the rocker with another brace as my quarter was off the car.

My car is on a rotisserie by the way.

I put my complete floor in from the bottom up. started underneath and slid forward to clear the rear frame rails and worked it in from there. A two man job for sure. Then all the jacking and bracing to get everything to lay flat before welding the frame rails and working my way forward.

I chose to put the braces in after the floor was in to get the proper fit and adjustments. There are many..

Haven't had time to post pics, but I will soon.