I have a Duster with a 10PT and I was wondering about adding the front frame rail braces. I've seen some where there are flat plates bolted to the firewall and the tubing gets welded to that or the tubing goes straight thru the firewall and gets tied-in to the pillars. I have no trouble going through the firewall but I'm unsure as to how to locate the holes so I'm not butchering up the car.

The previous owner had chopped a couple holes out of the firewall to get to the tranny mount bolts (A-body 440 with midplate) which I have since patched. The rest of the firewall is untouched.

Thanks