There are many "mothers of invention". While necessity often dictates development, so too have simple mistakes. Take, for example, forgetting to install/facilitate an updated frame-mount brake pedal and master cylinder assembly on a post-war Chevy before having the frame powdercoated and routing the exhaust. No problem, right? Simply incorporate some fashion of a firewall-mounted brake setup. That would be fine and dandy under one circumstance: You're not opposed to having a late-model master/booster hanging off the front of your firewall. In many cases, the answer is "no". OK, how about integrating an underdash setup? That too would be fine and dandy if it weren't for the fact that you'd already smoothed the exterior of the firewall, thus not visually allowing any means in which to attach...at least not a traditional manner, that is.
Hindsight reared mama invention's beautiful head in this particular situation, ultimately producing a panacea for not only the brake system dilemma, but nearly every issue that smoothing a firewall can create when it comes to mounting/attaching items. Sheetmetal pales in comparison to a piece of 3/16-inch aluminum plate—it also tears under any kind of significant load! With a plate panel mounted behind the firewall, your underdash accessorizing is almost unlimited, including the main reason why we're here in the first place: accommodating an above-floor resolution for not having re-incorporating the OE under-floor brake pedal assembly when the opportunity existed.
Jimenez Bros. Customs (JBC) starts off with a sturdy plate foundation cut to shape based off the parameters presented behind the upper-inner firewall (just below the cowl) mounted via captured nuts welded to the body. With such a solid base, a Classic Performance Products beefy swing-pedal setup is able to be attached without fear of any structural failure, even under the constant pressure it will be once the vehicle's on the road and the pedal pumped regularly. Further real estate is acquired for locating such items as the fuse panel, in this case those provided with the Keep It Clean wiring kit the 1947 Chevy in question is using, as well as the battery and master kill switch (also obtained from Keep It Clean).
JBC's inner firewall panels began more as a per-vehicle, custom-made deal. But after having done a number for 1949-54 Chevy cars and 1947-55 trucks (as well as Tri-Fives by the time this comes out), the panels are starting to make their way into the "catalog" category. That said, while JBC would love nothing more than to sell a ton of them to customers far and wide, we're going behind the scenes to show you how they made this one from start to finish! Use the following info to your own discretion.