Finally got my firewall patched up. Previous owner hacked it to hell to try to make the distributor fit. He cut it even down to the trans tunnel, so there was a nice opening right from behind the intake manifold, straight into the cabin. Now, the bottom is sealed, and the top is cut and a lip welded in which will seal directly to a cowl induction setup. Note that there is a separate metal box in the cabin interior where the cowl assembly goes in, so no holes feeding the interior, just two drain lines on the outer edges which run to the car's exterior. In other words, I didn't repair a little hole that won't stop fire and just replace it with a big one.