Here we're getting the rest of the the understructure match drilled, including the steel firewall support brackets. I had read somewhere that if you weren't careful, you'd end up with unacceptable edge distance on the holes in the firewall brackets. I couldn't really see at first how you'd improve the alignment of the firewall brackets, but if you use some C-clamps, you can get everything to line up properly for drilling, which is what I ended up doing. cool. After that, it's basically deburring, dimpling, and prepping for priming.