GMC firewall markings, Pontiac plant

[davem815]

I searched the forum and could not find any information about GMC firewall markings. I’m still learning on 60-66 trucks.

I recently purchased a 1966 GMC ¾ ton that appears to be all original. I do not have the build sheet. The fire wall paint is original with the original markings. I can figure out what most of the markings mean, but I have a couple questions.

4669: this must be a build sequence number. It appears on the firewall, warrant book (hand written) and engine valve cover.
4669 on valve cover: looks like 7669, but is probably 4669 with the 4 angled and partially scratched off.

Tinted W/S: is pretty obvious, tinted windshield

EWQ: not 100% sure on letters for this one. No idea was it means.

Comfort: Comfort cab

555, written over top of comfort: no idea was this means. Interior paint/cloth code?

686 written near transmission tunnel: no idea was this means.

Writing behind and hidden by power brake booster and circle around mounting bolt: I assume means power brakes

Writing behind and hidden by heater: I assume means deluxe heater


Can anybody explain what some of these letters and numbers mean? Even if you can’t, maybe these pictures will help document originality for somebody else. I can post more picture or take specific picture upon rquest.

Any chance some of these number are paint codes? Very unlikely, because what would be the point of adding paint codes after the cab had already been painted? This is a yellow two-tone that doesn’t appear to me to be a standard color. The '66 GMC yellow appear much darker, I've seen it called yellow-orange. I don't have an actual paint sample, I'm comparing it to a downloaded '66 paint chart.

[davem815]

more pictures.

What I know about this truck, built in Pontiac, delivered Jan. 1966. 3/4 ton, 305 V6, 3sp, power steering, power brakes, custom cab, side moldings, deluxe heater, two-tone paint, cloth seat, tinted windshield, laminated side windows, emergency flasher switch

[bruceman1968]

Dave, thanks for posting those pics. The Pontiac GMCs are fun because they wrote out a full description of the options as opposed to just a RPO code.
4669 is most likely the last 4 of the PVI number. Primary Vehicle Identifier numbers were assigned to each truck after it was ordered. So first the truck had a order number, then a PVI number, then a General Assembly number and then a Job number. Sometimes the GA number and Job number were the same.
The unique serial number is different entirely. It never appears written on the truck. Just on the vin tag, Protect o Plate, build sheet etc. Here is a good thread with more about the different vehicle numbers from Keith Seymore.
http://67-72chevytrucks.com/vboard/s...light=graffiti
No idea on the EWQ
Your right on the Tinted Windshield, (A11)
comfort is probably Custom Comfort (Z62)
I think your on the right track with the brakes and heater also.
555 Don't know yet. Anybody????? It could be a paint code. I don't know why but paint codes show up written on the finished paint often. Makes no sense, but it does happen.
686 probably the Job number.
Thanks again for posting those.

[VictoriaHardware]

I have a '65 Pontiac-built Chevy C80. In comparing pictures, mine has different handwriting but does have an "Ewt" in the trans tunnel, similar to your "Ewa" or "Ewq". I don't know what it means either.

It also has a seven digit number. I looked it up and it turns out to be a speedo cable p/n. The p/n is applicable to the truck. I guess it needed to be loaded from the bottom side and it was convenient to notify the operator that way.

[davem815]

Thanks for the responses. Great link to the thread with Keith's comments. I had never found that thread before.

GMC Pontiac plant built big trucks for Chevy, correct? I remember reading that in a GMC history book I have.

Anybody got input on EWQ? Or 555 over Comfort?

Any other GMC marking pictures?

[factorystock]

Originally Posted by davem815

Anybody got input on EWQ?

Any other GMC marking pictures?

Check out http://67-72chevytrucks.com/vboard/s...y+photo&page=8 post #185 , EW on cowl. It appears at some point in assembly, extra cost options were written on cab firewall to communicate with the line workers. This larger truck also has "2 sp" for 2 speed rear axle, and "air" for air brakes. My first guess at "EW" would be emergency switch or 4 way flasher switch equipment?

[60-66]

Originally Posted by factorystock

Check out http://67-72chevytrucks.com/vboard/s...y+photo&page=8 post #185 , EW on cowl. It appears at some point in assembly, extra cost options were written on cab firewall to communicate with the line workers. This larger truck also has "2 sp" for 2 speed rear axle, and "air" for air brakes. My first guess at "EW" would be emergency switch or 4 way flasher switch equipment?

Just going to through my guess in the ring. Electric Wipers, 2 speed. On GMCs this was an upgrade that included, windshield washers , which also included drilling the firewall for the hoses and adding the squirt nozzles. For the Hazard Flasher , nothing needed to be drilled or modified , just hang from the dash like the accessory flasher or put in the existing hole in the dash. Just a thought. Great thread by the way !!

[davem815]

factory stock, thanks, EW could be "emergency warning" flasher switch because the truck is equipped with one. And maybe the Q or 0 could be a separate code.

VictoriaHardware, does your C80 have emergency flasher switch?


555 probably is a paint code. I forgot Classic v6 GMC posted a picture of special order paint color W83E5555 (of which 555 is the unique identifier) yellow paint which seems to match mine. I forgot about it because I was not able to cross reference that number to any paint code.

Bruceman1968, I'm sure you know this, so I'm only documenting this for anybody's future searches. GMC code for tinted window is 0163, Comfort group is 0171.

I'm not sure what the difference is between 0171 Comfort Group and 0170 Interior Convenience Group. Both are separate options, so it looks like you could order either or both, unless Comfort Group ($30) was a lower level option less included than 170 Interior Convenience Group ($155)

[VictoriaHardware]

Originally Posted by davem815

VictoriaHardware, does your C80 have emergency flasher switch?

Yes it does

[60-66]

Heres some from a 1962 GMC.

[par4tom]

Very cool post...interesting!!!