1968 Firewall Hole ID

Got a PM asking for the decoder ring to a couple photos I did. This is based on a 68 S code manual GT. Could not find the original post.

Any corrections or clarifications appreciated, can amend the list if needed.





A – Power brake booster, red (manual cars use only two side holes on booster, bolts thru other with plate on firewall)
B – Steering column – 4 sheet metal screws
C – Washer hoses (small hose on top)
D - Engine feed wiring harness
E – Speedometer cable
F – Clutch rod (blank not punched out on Automatics)
G – Emergency brake (also clutch spring return bracket on manual cars)
H - Accelerator pedal grommet
J - Accelerator bell crank – 3 sheet metal screws
K –Brake line clip
L – Fuse block, 2 sheet metal screws
M – Unsure – not used on either of my 68 S codes or 68 C code, maybe 6 cylinder use
N – Pedal support to firewall – 2 sheet metal screws
P – Brake Line Clip
Q – Alternator Wiring Harness / Transmission Neutral Switch Harness
R – Firewall Pad Retainer
S – ??? (see pic next post)
T – Heater – 4 studs w/stamped nuts w/sealer (heater equipped cars only, not A/C cars or heater delete. For A/C cars oval plate to right is punched out)
U – Heater Hoses (on all cars, for A/C holes were capped with rubber plugs)
V – Brake line clip
W – Firewall pad retainer
X – Unsure, think it may be dimple for 6 cyl accelerator rod bracket, not used on my V8’s
Y – Heater motor shield, used on A/C cars and left on many big blocks
Z - Engine ground strap

Some added holes from another pic I saw digging up the two above, a bit clearer in primer...



1 – AC heater box mounting studs (2 dimples)
2 – AC water control valve (2 screws)
3 – Radio Suppressor Strap
4 – Hood turn signal wiring (San Jose cars)
5 - Cowl weatherstrip (7 places)
6- Windscreen washer nozzles
7 – Washer hose tee
8 – dimples for AC cover plate (not marked, visible near heater blower mount holes and under the lower heater hose hole)
9 – dimples for AC vacuum canister, 3. 2x for screws and 1x for the large hole for the can hose connection fitting)
10 – wire retainer mount, transmission neutral switch (auto trans only) (#382175)
11 – wire retainer mount , trans neutral switch and coil/oil harness (#374320)
12 – wire retainer mount (hood louver signals)
13 – hood signal harness retainer mounting screw (hidden)
14 – heater wire retainer clip (heater power wires)

Many other dimples holes (black circles) I could never ID....

On an AC car the horizontal punch-out plate, to the right of the huge hole on the left, will be open. I think the two heater hose holes will be closed, but I'm not sure - they may have rubber plugs in them.

Ah ha, I found a photo.
They appear to be rubber plugs.

Yep, and 6 cylinders will have different items. And manual vs clutch differs (hole F will be closed on a automatic car). Have updated the initial lists.

To do a comprehensive listing would take pics from a few different cars. 6, small block, big block, manual, auto. I doubt body style changes much (but I do need to add where the convertible top feed would go thru....)

If others can provide them we can build a set... I'm happy to mark up the pcs with similar numbering...

The level of information from this site is amazing!! You guys never cease to amaze me!!

Rob

A/C photo: The 2 heater hose holes ARE used on an A/C car. Just different hose routing.

Neil

Thanks Rob, coming from you that is a high compliment.

Neil,

Can you clarify?

I thought the non-AC heater holes were blanked off with rubber plugs on AC cars.

The heater core in the AC box has connections thru the optional oval punch-out, and the evaporator connections go thru where the heart motor sits on a standard heater optioned car?

I think in your photo you can see the unused original heater holes behind the transmission dipstick?

#4 is used for hood signal wire mounting on a San Jose cars. 13 is used on Dearborn and Metuchen cars.

There also is a dimple in the #1 aria for a vacuum hose support bracket on AC cars.

I'll get another photo tomorrow. (Both my C/S's are factory A/C)

Neil

dalorzo_f said:

Thanks Rob, coming from you that is a high compliment.

Neil,

Can you clarify?

I thought the non-AC heater holes were blanked off with rubber plugs on AC cars.

The heater core in the AC box has connections thru the optional oval punch-out, and the evaporator connections go thru where the heart motor sits on a standard heater optioned car?

I think in your photo you can see the unused original heater holes behind the transmission dipstick?

Click to expand...

Yep, the holes behind the dipstick are the heater hose holes.

Item 4 updated.... thanks! I found that in double checking my own phots once you mentioned it!

Now to fix the GT/CS, S convertible and GT coupe... all San Jose and I did them wrong!!! :tongue:

And I am unsure if S is firewall pad or a option wiring port... and the pad is the one to the left.

Anyone know where the convertible wire originally went? My '68 uses S but am not sure if that is correct, or just where I ran it a decade ago when I restored the car... I think it may be the black circle dimple to the left of S...

Oh MY GOD!!! I bow to the information on this subject. And Richard that is a huge compliment to me who does not deserve such high praise!! Not in the concurs world that you guys are amazing in!

Way to preserve and authenticate our hobby guys!!

Rob

It's like the gods have spoken because I really needed this information myself.

Hey, I ain't no "concours" guru, just someone who's tinkered with these cars far too long who tries to make mine stay as they were (for the most part, the EXP is a vast digression! But "period correct" in many ways... :smile. Which is getting harder to do as repro parts/panels are probably now 50% of all "Mustangs" out there.

And share what I see/know/think...

IMHO these days anyone documenting "original" is doing the future a favour as from what I see here in Australia the general trend it "it looks like a Mustang" ... from 10 meters... that's 32 feet, 9 45/64 inches to you "Yanks" ( I love throwing US units at Aussie engineers and designers I work with, fractions in dimensions just spin them out...:wink: )

No "gods", don't support that concept in the hobby (as the $ in restoration are driving some to define themselves as such, but appreciate the sentiment) just happy to share and know it helps others, many have helped me over the years... only fair to do the same.

As noted any corrections/amendments/adds appreciated...

Should we do one on the aprons and radiator support?

Great information! And timely... my heater core is leaking... and I've got an AC car... I'm anticipating soon entering the next level of Dante's "fixing-my-stang" hell...

Thanks!

Thank you for this! very helpful.

Excellent post! Thanks! I added a link in the "Restoration Reference Archives" forum.

dalorzo_f said:

Hey, I ain't no "concours" guru, just someone who's tinkered with these cars far too long who tries to make mine stay as they were (for the most part, the EXP is a vast digression! But "period correct" in many ways... :smile. Which is getting harder to do as repro parts/panels are probably now 50% of all "Mustangs" out there.

And share what I see/know/think...

IMHO these days anyone documenting "original" is doing the future a favour as from what I see here in Australia the general trend it "it looks like a Mustang" ... from 10 meters... that's 32 feet, 9 45/64 inches to you "Yanks" ( I love throwing US units at Aussie engineers and designers I work with, fractions in dimensions just spin them out...:wink: )

No "gods", don't support that concept in the hobby (as the $ in restoration are driving some to define themselves as such, but appreciate the sentiment) just happy to share and know it helps others, many have helped me over the years... only fair to do the same.

As noted any corrections/amendments/adds appreciated...

Should we do one on the aprons and radiator support?

Click to expand...

All right, "ambassadors of the hobby". No that is not a reference to a Rambler!!

Sharers make the world go around!!

Rob