[jonzcustomshop]

I took some measurements off a 65 using the seat mount holes to triangulate the inboard holes. I drilled all the way through, then made the upper hole bigger to go around the support washer indentation, then used a 5/8 hole saw for the lower hole.

since I couldn't weld the support in the brace like the factory did, I just welded it to the washer , then welded the washer to the floor.