i got the pedals and the triple master mounted today. i still need to work on bracing the pedals so i'll have some more pictures in a few days.
the chevelle uses a very good mounting system for both the column and the stock pedals. there is a beefy piece that ties both into the firewall and cowl area making both nice and sturdy. i attempted to use this piece to mount the pedals, but even with most cut away, the pedals didnt sit high enough to clear the column (pedals would clear, but the bias adjuster sits next to the pedal and needed the pedals to sit higher).
so the current plan uses a 3/16" plate on the back of the firewall, along with 3/4 x 1.5" .120 tubing to brace it back to the column mount. this will all take the place of the stock piece. currently, i only have the plate mounted and its sturdy as hell, but i know i will still get some flex. also, since i though i was using the stock mount, i welded the shaved piece around part of the original firewall. since that didnt happen, i had to cut out a section and weld it completely flat. i hope to get the rest done in the next few days.