Firewall assembly markings

[IT Cowboy]

My truck was repainted with the goal of faithfully recreating its original factory finish. When I purchased it, these markings were present on the firewall. I later tracked down the owner who had the repaint done, and he explained that he photographed the truck beforehand and carefully reproduced the markings as they originally appeared.

At first, I wondered if they might have been approximated from another truck or recreated from memory. However, they correspond exactly with my truck’s engine, trim code, options, and SPID information. That confirmation makes them especially meaningful, as most of these original markings are typically lost or erased over time. It’s a small but authentic detail that helps preserve the truck’s original identity.

[Casper42]

for what its worth, not all trucks had the markings...or at least to the new buyer. I worked at a Chevy dealership in the early 80's and as a car detailer, we were instructed to remove these in the prep stage right after delivery. I suspect Chevy had specific guidelines for dealerships to follow for preping new vehicles, and this was one line item to follow - but all didn't follow

My '72 C10 has all the factor paint on the firewall, and there are zero remnants of the "caulk marks" (Atlanta build)

[IT Cowboy]

Originally Posted by Casper42

for what its worth, not all trucks had the markings...or at least to the new buyer. I worked at a Chevy dealership in the early 80's and as a car detailer, we were instructed to remove these in the prep stage right after delivery. I suspect Chevy had specific guidelines for dealerships to follow for preping new vehicles, and this was one line item to follow - but all didn't follow

My '72 C10 has all the factor paint on the firewall, and there are zero remnants of the "caulk marks"

I also have the "OK" marked on the radiator mount. I think these add a bit of nostalgia and authenticity to the truck and it is fun to think about the assembly process and how these were the shorthand or code for the assembly process.

I am pretty sure the "T2" markings on each side were the trim code and the Highlander level 2 package.

['68OrangeSunshine]

I bought my '68 C/10 Stepside in 1973. Fremont truck. Obvious fleet buy unit. I don't remember if it had any firewall crayon graffiti, but if it had I would have rubbed it out over 50 years ago.

[davischevy]

The markings on the cowl was a St Louis Assembly plant thing.

[Steeveedee]

When I worked for Chevrolet dealers, we had our own marking system for stock number purposes. I never paid attention to whether there were factory markings, tbh.

[WorldsCrappiestTruck]

I’m no expert but I don’t think I’ve ever seen specific RPO codes in chalk like the ones recreated. Maybe someone will prove me wrong.

The only markings I’ve seen and are things like the model of the truck, the color code (in my case 507 light blue) then other cryptic stuff. This truck has 1116 then had 495 on the lower center firewall behind the engine….whatever those mean.

[mr48chev]

All I am gong to say is that years ago my wife and I went to a regional Mustang event and a lot of the participants with stock early Mustangs were wetting on their shoes because there was an old dude there who had been an inspector on the Mustang line and he would verify the marks on the firewalls. That told me right there why I would never make it as a restorer.

[IronCanine]

For anyone interested, there are several threads on this forum that go into the weeds on factory markings. A simple search will get you to them. Procedures and markings varied from plant to plant. Larry is correct, St. Louis was the most prolific. Their firewalls usually denoted trim level (2T, 4T..probably short hand for Z62 and Z84), model number, engine RPO, trans RPO and whether or not they had power brakes. A/C was denoted under the heat exchanger box on so equipped models and most of them had the actual paint color written on the bare metal there. St Louis didn't stop with the firewall, the build sequence number (and model number) was written on the chassis. It was also on the core support and the back of the gauge cluster. Those are the big ones, but there was more.

Flint wrote on the firewall, but less info. Fremont actually wrote in the wet paint on the firewall.

A lot of fun details in the individual assembly plant protocols.

[IT Cowboy]

Mine is a St Louis truck so that explains why my firewall looks like railcar out of the eastside. It was cool for the previous owner to document and recreate them. If you have them then the numbers usually match the codes on the SPID in some manner or they are a shortcut of the SPID codes.

[Keith Seymore]

Originally Posted by WorldsCrappiestTruck

I’m no expert but I don’t think I’ve ever seen specific RPO codes in chalk like the ones recreated. Maybe someone will prove me wrong.

You would be incorrect. Many of the markings are obviously engine RPOs, trans RPOs and trim levels.

Some grease pencil marking threads:


http://67-72chevytrucks.com/vboard/s...light=sequence

http://67-72chevytrucks.com/vboard/s...light=graffiti

http://67-72chevytrucks.com/vboard/s...light=graffiti

http://67-72chevytrucks.com/vboard/s...light=graffiti

http://67-72chevytrucks.com/vboard/s...light=graffiti

http://67-72chevytrucks.com/vboard/s...d.php?t=545345

http://67-72chevytrucks.com/vboard/s....php?p=6543084

Originally Posted by WorldsCrappiestTruck

The only markings I’ve seen and are things like the model of the truck, the color code (in my case 507 light blue) then other cryptic stuff. This truck has 1116 then had 495 on the lower center firewall behind the engine….whatever those mean.

I'm thinking the 495 is the build sequence number (an abbreviation of the full six digit sequence number, like "313495", or 123495").

My own truck was "number 87".

K

[Keith Seymore]

Originally Posted by mr48chev

All I am gong to say is that years ago my wife and I went to a regional Mustang event and a lot of the participants with stock early Mustangs were wetting on their shoes because there was an old dude there who had been an inspector on the Mustang line and he would verify the marks on the firewalls. That told me right there why I would never make it as a restorer.

I guess I'm that guy (only for truck).



46 years in Product Design/Development and vehicle assembly, across 12 GM assembly plants (including Flint, Janesville, St Louis, Oshawa, Pontiac).

K

[IT Cowboy]

Originally Posted by Keith Seymore

I guess I'm that guy (only for truck).



46 years in Product Design/Development and vehicle assembly, across 12 GM assembly plants (including Flint, Janesville, St Louis, Oshawa, Pontiac).

K

Wow, tell us more and share if you would please. Is the story about a pop bottle in a frame true or trucks being built on Fridays.

[Steeveedee]

Not a bottle, but a can, in a '64 Impala a friend of my dad's had. It had an occasional clank at the rear of the car. Not until it got hit and some metal moved was the Pepsi can found. I don't recall where it was, but it wasn't found until after the accident.

[Keith Seymore]

Originally Posted by IT Cowboy

Wow, tell us more and share if you would please. Is the story about a pop bottle in a frame true or trucks being built on Fridays.

This is the one I was looking for:

https://67-72chevytrucks.com/vboard/...ighlight=story

But there's some similar good stuff here, too:

https://67-72chevytrucks.com/vboard/...ighlight=story

https://67-72chevytrucks.com/vboard/...ighlight=story

https://67-72chevytrucks.com/vboard/...ighlight=story

https://67-72chevytrucks.com/vboard/...ighlight=story

https://67-72chevytrucks.com/vboard/...ighlight=story

https://67-72chevytrucks.com/vboard/...ighlight=story

https://67-72chevytrucks.com/vboard/...ighlight=story

https://67-72chevytrucks.com/vboard/...ighlight=story

https://67-72chevytrucks.com/vboard/...ighlight=story

[Keith Seymore]

And then, of course, my bio and build thread here:

https://67-72chevytrucks.com/vboard/...d.php?t=342926

As well as some stuff about growing up with Pontiacs:

Pontiac Bio: https://forums.maxperformanceinc.com...d.php?t=560524

"Old Wives Tales": https://forums.maxperformanceinc.com...d.php?t=556607

[Keith Seymore]

This is a good one, too:

https://forums.maxperformanceinc.com...d.php?t=549318

[IT Cowboy]

Originally Posted by Keith Seymore

This is a good one, too:

https://forums.maxperformanceinc.com...d.php?t=549318

I am going to hijack my own thread and ask you about the factory finishes on the trucks. My truck was repainted in what the previous owner called factory finish style. It has quite a bit of orange peel on it and it is fairly thin. I was always told that trucks were trucks and GM ran them through and didn't give a lot of attention to the finish on them.

[72c20customcamper]

Originally Posted by IT Cowboy

I am going to hijack my own thread and ask you about the factory finishes on the trucks. My truck was repainted in what the previous owner called factory finish style. It has quite a bit of orange peel on it and it is fairly thin. I was always told that trucks were trucks and GM ran them through and didn't give a lot of attention to the finish on them.

That era even cars finish wasn’t that good . Worked at my uncles body shop from 1977 -1986 full prior to 77 was summers and after school . My cousin bought a 1977 corvette new in the summer and we stripped it that winter and repainted it . Original paint was terrible . Orange peel was normal in all lines even a run or two was not out of question . My 68 c20 had runs on the dash and the rear pillars .

[Keith Seymore]

Originally Posted by IT Cowboy

I am going to hijack my own thread and ask you about the factory finishes on the trucks. My truck was repainted in what the previous owner called factory finish style. It has quite a bit of orange peel on it and it is fairly thin. I was always told that trucks were trucks and GM ran them through and didn't give a lot of attention to the finish on them.

I suppose - especially the 67-72 models.

It was single stage, and there was no after treatment (except for whatever flow you got from the bake ovens). Probably better described as thin in some spots and heavy/runny in others.

It progressively got better, especially when you moved into the base coat/clear coat era (starting 1989 model year for trucks).

K

[Keith Seymore]

Originally Posted by 72c20customcamper

That era even cars finish wasn’t that good . Worked at my uncles body shop from 1977 -1986 full prior to 77 was summers and after school . My cousin bought a 1977 corvette new in the summer and we stripped it that winter and repainted it . Original paint was terrible . Orange peel was normal in all lines even a run or two was not out of question . My 68 c20 had runs on the dash and the rear pillars .

Corvettes were so bad that you couldn't get one in black.

If you wanted a black car they would build it in primer and you'd have to get it painted after you got it.

K

[Keith Seymore]

My Chevelle (1974, built in Oshawa) did not get any paint inside the trunk under the rear package tray. It is still bare even today.

It had been crashed in the assembly plant. The first time we pulled the fenders off to paint them there was bondo around the wheel opening on one side.

My GTO (1965, built in Pontiac) has the worst original paint I have ever seen on any vintage vehicle. There are hairs in the paint, handprints in the wet paint in the hood, and a big swiped area on the trunk lid that looks like some one wiped some solvent over it. Those are all still there to this day.

K

[Keith Seymore]

For show vehicles we used to "flatten" the paint: the guy would take a tongue depressor wrapped with some 600 grit sandpaper and knock all the high points down, and then wheel it out. That happened at the Milford Proving Ground paint shop, or at the Design Studio, long after the vehicle left the assembly plant.

When I had to fluff and puff vehicles for upper management I had a list in my head of all the things I knew I would have to do, even before I got it:

* fix wind noise
* balance and vector tire/wheel assemblies
* zero balance driveline
* fix the paint
* fix all squeaks and rattles
* etc

K