I'm at the point where I need to weld up any open holes in the firewall of my '67 so I can have it smoothed by the paint and body guy. The problem is that I can't seem to figure out what a few of these holes are for. I have an assembly manual and the drawings are not always clear. I also looked through quite a few of my magazines and these particular holes are usually obscured by the brake vaccuum booster. I have posted 2 pics that show the holes in question (Holes "A" thru "F"). Any help is appreciated.

I'm not sure what all the holes are for but my advice is if you don't weld them up and don't need them you wont be able to after you paint.You can always drill a hole if you need it but its hard to plug after paint. I see the DSE wiper motor, are you using AAW if so they made me a new set of wires to go through the fuse block instead of drilling a hole for the harness that comes with it .I used the 'A' hole for my lokar throttle cable. Also I wish I would have welded some of the holes on the inner wheel houses, I had to plug them with rubber plugs which doesn't look to hateful. You really need to figure in all you aftermarket components that your using and go from there.

On mine if the holes looked to perfect to not be factory I didnt weld them up. I just welded the ones that were obviously from self tapping screws or a drill bit. I can get some rubber plugs if I happen to be wrong on some of them.

Someone has drilled all them holes in there for something at one time. I looked at the 69 and I dont have any of them holes. Mine is already smoothed but I looked at it from the inside. I would weld them all up.

David,
I know what you mean about the fender wells. I welded up all the holes and indententions. Also the big hole under the battery tray since the battery is going in the trunk.

Yeah Mike, I kinda messed up but all in all it turned out alright.It was to late once it was painted on the inside of the wheel houses I used spray in bed liner and there was no turning back.

Did you look at the firewall piercing page in UPC 0 in the AIM? I don't have a 67 AIM, but based on the 68 AIM...

D&E look like the 68-69 holes for a 6cyl throttle cable and attaching screw, but you have a 67 right?

C and where you have your throttle cable look like the location for RPO K30 speed control.

B is too low for anything in the 68 AIM, but it looks close to where the carpet guard attaches from the inside. 68-69 use screws, but does 67 use something bigger to attach the carpet guard?

A isn't in the right place for M20, but the hole sure looks factory.

F looks like the 68-69 rally sport vacuum line hole, or a power feed for power windows or vert top.

Thanks for the replies and ideas.

Did you look at the firewall piercing page in UPC 0 in the AIM? I don't have a 67 AIM, but based on the 68 AIM...

I don't seems to have this diagram/page in my '67 AIM. My book is nothing more than a 3-ring binder with all of the pages copied so a page may be missing. (I bought it from Classic Industries so I doubt that it's a bootleg copy)

Someone has drilled all them holes in there for something at one time. I looked at the 69 and I dont have any of them holes. Mine is already smoothed but I looked at it from the inside. I would weld them all up.

I failed to mention that this is a replacement firewall. So some of these may be tooling holes and it may not necessarily match the OE firewall. Welding the smaller holes up will probably be my plan. The only one that concerns me is hole "F" next to the fuse box. I would hate to weld it up and then find out that I need it for something. I will probably leave it as is and plug it later (with a separate plug) since it is somewhat hidden.

You really need to figure in all you aftermarket components that your using and go from there.

I already have all the aftermarket parts identified. I think that the only thing I don't have dry-fitted at this point is the electrical harness... and I'm going to skip putting that in at this point. I don't think that it makes sense to go that far... but I may be wrong.

I too recommend welding them up as you can always open new ones in a different/more hidden location later on. I welded a few up, but left a lot open and didn't think as far ahead as you and now have a combination of holes that I don't need, plus others that I have used for other things.

I also have the DSE wiper and hydroboost, although I have a '68 and mine looks a bit different. But I have some of these same holes:

'C' - This location for me, assuming its the same spot, is a flattened area with two dimples in it. Its looks like a pig's snout to me. I had to drill out these two holes for my distributor wiring and coil wire. I am putting in a cable throttle, so I hope I won't need it for that.

'D' and 'E' - I have these two holes and also used them, enlarging them slightly and used them for the pass-thru for the DSE wiper wiring. There was a plastic grommet looking thing that stuck out about 1/4" in the 'D' hole on my car, with a screw holding this plastic contraption in the 'E' hole. The screw and plastic piece were installed from inside the car and the screw sticking out of the firewall looked bad to me, so I removed the thing and drilled them out and ran wires through them both.

'B' - This is exactly where my carpet pad screw comes out, but the hole here looks too big. Might be due to aftermarket firewall though.

'F' - I also have this hole; my '68 is an RS and I don't recall where the vacuum lines came out, but I plugged this hole which for me is impossible to see as its right next to my hydroboost bracket. I don't use vacuum any more.

-Kevin

Thanks all. It looks like everyone has some good ideas on how to handle it. Now all I have to do is remove the engine that I was checking the fit on and off to the bodyshop it goes.

Bill, The hole that is " F " could be used later for some wiring if need be. You could put a rubber grommet in it and run your wires thru it. Then up under the fender between the fenderwell and fender.