This could have gone in a number of different areas, but I am just guessing this section would get the most views (and help), so here goes.

There are quite a lot of holes in the firewall of my 70 that may or may not be needed. Most are factory, but some were added or enlarged by the past owner(s) for running gauge lines, extra brackets, and the installation of 2 aluminum panels that covered most of the firewall.

I have my ass'y manual out and I have scoured over the 4 separate pages that reviews most of the holes, but not all of the holes.

My plan is to weld up all of the ones that were added, but unnecessary, and all of the ones that were "stock" but not necessarily needed.

Another idea floating around in my gray matter is using a button headed plug for the larger unused holes that might cover the hole and could be sealed at the stem and on the interior side.

I DO NOT want to smooth the firewall, just clean it up. I might want to smooth out some of the "dimples" that were never drilled and/or will not be used, so if you have any experience in the best products, etc. please speak up.

ex-Not going to use the stock firewall insulation, don't need all of those holes.
Going to install a heater delete plate with aftermarket AC/Heat. Keep those holes.

The assembly manual has 4 different pages of the diagram. In my version the newest notation is the 4th page with 4 notes and a 6-2-69 revision date.

There are sections A-N. Each lists an RPO # (like C48 or U69 & U79), identifies the hole, the size, the location, and application (V8, L6, etc.)

Is there another page I missed that lists the use of all of the holes or has anyone done this before and has a diagram or photos to share.

If not, is anyone interested in reviewing with me and let's make one up?

Thanks in Advance,
Fred

Some of the holes were for the rubber plugs that held the firewall insulation in place, what are you gonna use there?

Some of the holes were for the rubber plugs that held the firewall insulation in place, what are you gonna use there?

Welds

Fred, that's exactly what I plan to do with my firewall.

I need to consult my assembly manual soon, see if I can make any sense of it all.

there should only be a few holes that you need- speedo cable, throttle cable, heater/AC wiring, heater core, brake pushrod, clutch linkage.
anything else is just extra.

I think I will map it all out and post a detailed "schematic" for the hole of us. l:)

That would sure speed up my hole project!

That would sure speed up my hole project!

Don't give up your day job. l:)

OK gang. Like Where's Waldo

I marked all of the holes with numbers and shaded sections.

What I am attempting to do is fill in:

the holes normally used by the firewall insulation "pins", holes
the holes that were drilled by past owners that don't do anything anymore
Holes that were enlarged (ex-35 has a hole that was enlarged just below the sq. throttle cable hole)

Areas of particular interest #'s 25, 26, and 35

So if you have some time and care to reference against your 70 Chevelle BBC, stick, non-a/c firewall, I would greatly appreciate it! :D

Ex-
Make a list
#
Need or not needed
What used for

http://i180.photobucket.com/albums/x141/fppb1/WhatRallTheseHolesFor2.jpg

Attachment photo below is a larger format

"WOW" Fred that took some time to do, good job.

Coming from you, that is genuinely appreciated! :thumbsup:

So get to work and get me sum ansirs! l:)

Coming from you, that is genuinely appreciated! :thumbsup:

So get to work and get me sum ansirs! l:)

I was just getting ready to do something and the middle Son calls and he has a box of motorcyle parts to bead blast, jugs etc.

No wonder I can't get anything done.:D

Hunny-dos or Sunny-do's, the best to-do is do them! :D

Firewall ain't going anywhere fast.

Aw C**P!...there's no # ___ or ___. Let's see how long that takes you to figure it out!

Only those posts with actual answers count. ex- # __ is used for.

Nice job on that! - now if somebody'd do that for a '66 ... :D

Updated pic. I realized that I had mis-numbered some holes.

So here's the list


Factory-Not used-Covered by the blower housing
Factory-Used to secure the blower housing
Factory-Not used-Covered by the blower housing
Factory-Notused-Covered by the blower housing
Factory-Not used-Covered by the blower housing
Factory-Used to secure the blower housing
Factory-Firewall insulation clip
Factory-Heater box bolt hole
Added by past owner-unnecessary
Added by past owner-unnecessary
Factory-Heater box bolt hole
Factory-Heater box bolt hole
Added by past owner-unnecessary
Added by past owner-unnecessary
Factory-Heater box bolt hole
Factory-Firewall insulation clip
Factory-Heater box bolt hole
May be an extra hole or used to hold on the plastic channel-or unnecessary
May be an extra hole or used to hold on the plastic channel-or unnecessary
May be an extra hole or used to hold on the plastic channel-or unnecessary
Added by past owner-unnecessary
Added by past owner-unnecessary
Added by past owner-unnecessary
All added by past owner-Was used for man. choke-unnecessary
All added by past owner-Was used for man. choke-unnecessary
May be an extra hole or used to secure plastic channel-or unnecessary
May be an extra hole or used to secure plastic channel-or unnecessary
Factory-Firewall insulation clip
Factory-Firewall insulation clip
Added by past owner-Used to secure added connection block-unnecessary
Added by past owner-Used to secure added connection block-unnecessary
Added by past owner-unnecessary
5 holes-2 Factory, the sq. one for accel. cable and the one to the immediate left of the enlarged hole. That one was Factory but looks like it was never used. The one to the bottom left and the one to the right of the enlarged hole were added by past owners. The enlarged hole was added by past owners and used as access for mech. oil and temp lines-Other than accel cable hole, the others appear to be unnecessary
Factory-Firewall insulation clip
Factory-Firewall insulation clip
2 holes-Large, Factory-Firewall insulation clip. Small added by past owner-unnecessary
Factory-Firewall insulation clip
Factory-Firewall insulation clip
Looks like it was added by past owner. Compared it to the fasteners for the fuse block, could not find a need-unnecessary?
Added by past owner-unnecessary?
Looks to have been added by past owner-unnecessary?


So if anyone could confirm the need for the addition small drill holes in 36, 39, & 41 and advise which of the holes 18, 19, 29, 26, & 27 are actually used to attach the plastic channel, we'd be all set. :thumbsup:

Whadidiwatsemitimeorwhat? l:)

20/27 are the screw holes for the wiring gutter

32 is a bolt hole for a clip to hold the washer fluid line.

36/41 (small holes) were screw holes that keep a wire loom in place on the interior side.

37/38 are for the e-brake pedal mount.

You totally missed the holes below 34, they're for your accel pedal.

Nice job on that! - now if somebody'd do that for a '66 ... :D

Mid July 66--Fremont--327/PG car--Malibu trimmed ElCamino (Custom?)
No gages-or power accys, except, power steering, radio
http://i275.photobucket.com/albums/jj289/Bryan59EC/66holes.jpg

Yellow circles are the firewall insulation pad retainer holes ( I missed one -- just below and to the right of the right side purple circle--appears to be a little grey boob)

Blue circles are wire gutter screw holes

Purple circles----had little pieces of tape over them----appeared factory applied

Black circle-----fender welded nut

Green circle----heater support screw---from inside the car

20/27 are the screw holes for the wiring gutter

32 is a bolt hole for a clip to hold the washer fluid line.

36/41 (small holes) were screw holes that keep a wire loom in place on the interior side.

37/38 are for the e-brake pedal mount.

You totally missed the holes below 34, they're for your accel pedal.

Good catch on 37/38. I knew that when I was looking at the car, but messed up in the list! :thumbsup:

On my car 32 was used to hold a terminal strip, so good to know that washer hose need.

ok where's the hole for the tach lead?

Here's what I did to my '67.... Could not stand looking at all the unused holes!! Or the seam for that matter.

http://i32.photobucket.com/albums/d33/pezzman123/PezzCar006.jpg

http://i32.photobucket.com/albums/d33/pezzman123/6e4976af.jpg

I agree. I need that done for a 66 as well. However, I did figure out a few holes for the Backup Lights, Oil Gauge and Tachometer.

http://i450.photobucket.com/albums/qq229/Camaros-n-Chevelles/1966%20Chevelle%20SS396/1966ChevelleSSFirewall002-1.jpg

Here's what I did to my '67.... Could not stand looking at all the unused holes!! Or the seam for that matter.

http://i32.photobucket.com/albums/d33/pezzman123/PezzCar006.jpg



That's exactly what I have been thinking of doing vs a fully smoothed firewall. Love it! :thumbsup:

Fred, do a favor for us other 70 owners and post your finished product to complete this thread. Thanks