I'm thinking about mounting my fuel pump on the firewall since my stock pump failed and one of the bolts holding it in place rusted away . So I pulled out the seats and backpad to find a good place to drill a hole for the pump bracket mounting bolts and noticed that there are two small holes already in the firewall and the surrounding sound-deadening material. They don't seem to go through to the other side but are clearly there for a reason. Any idea what they are for? The car is a 74.

From memory I think there was a bolt went through there to hold the soundproofing in place on both sides of the firewall. I ditched mine on the engine side and replaced it with more modern sound deadening. We'll see if I'm right shortly??

Here is my fuel pump mounted on firewall. Used long bolts from behind back pad with large fender washers.

IIRC there are 4 phillips head screws near the bottom of the back pad (2 behind each seat). Could those be the holes for the screws?

No these holes are different from the four backpad screws. It makes sense that they would be for screws that hold up the sound deadener though. Maybe I should add some?

JawjaPorsche, you don't happen to remember to remember the length of the bolts you used? It would be great to know that ahead of time, with fuel likely dripping out.

Holes in the firewall higher than about 4-6" from the bottom should be ignored, as the pump needs to be mounted low on the chassis.

The Cap'n

I can't remember what I had for breakfast! Seriously, I think they are six inches but not sure. Did this 20 years ago! You can always get a little longer and cut them if too long. I used an extra coil bracket I had for the fuel pump holder. Used rubber between bracket and pump to silence pump vibration noise.