How I repaired my rusted out body mounts on my '68 Firebird.

 Original hole was rusted out to about 1.75",  it's supposed be 1.50"

Bottom View

I fabricated this repair bracket from 1/8" plate.  It fits both sides.

I also made a special spacer washer the same thickness as the bracket to make the bushing fit properly.

Repair bracket in position.

Welded and painted with POR.

Completed frame.   Next to install the new PST bushings and 1.125" sway bar.