I decided to attach the sill portion with bolts drilling slightly oversized holes in the brace and then tapping the holes in the native rocker sill. I trimmed the edges to fit as perfectly as I could, filled underside contact areas w/panel bonding epoxy (E6000), then put the bolts in. I welded the shafts of the bolts and cut them flush with the brace before completing the welds around the bolts, edges at the fore/aft frame bars, and along the floor pan portion.
With the roof seams welded and braced, and the inner rocker panels strengthened, this should significantly reduce the torsional weakness inherent in this design w/o having to spend $1200+ on an aftermarket kit …at least that’s the hope/plan.
I forgot to mention, the rocker braces were made out of 3/16 steel. Adds a bit of weight to the car, but still far less than one of the stiffening kits.
Cool idea. I would like to do something like that too.
what size metal?
Lots of pics of the install please