Help decode the firewall? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

CST*TEN in Katy · 10-27-2007, 02:28 PM

I can figure out most of the markings on the firewall. I guess some assembly plants (mine was from St. Louis) used this instead of a build sheet.
CE10934 would be the model.
LS9 is the engine
M49 is the TH350
A/C is fairly obvious.

What is the T4 and 4T on the left and right sides? It doesn't seem to correspond to anything on the glovebox sticker. Except all the RPO codes have a 4 in front of them. 4 what?

There was also ome marking I found on a rear cross brace over the axle that probably designated the axle ratio, but I blasted and painted over it.

BACKYARD88 · 10-27-2007, 05:22 PM

Still trying to figure this one out huh. I don't have any idea what it means but I'm going to try and find out. It's been bothering me since the meet

Longhorn Man · 10-27-2007, 08:16 PM

Could be something like assembly line number and shift number... or something like that.
No tellin.

roger0080 · 10-28-2007, 11:40 PM

Usually you see "2T" when it is a two tone paint job: white cab, colored body.

Maybe for the fancier paint combo like yours, it's marked "4T" for four tone ? Haven't seen what the firewall markings are for a paint job like yours of white/dark gold/white. Maybe the "4T" is figured like this:

First tone = white cab top
Second tone = dark gold (hood/top color)
Third tone = white side body
Fourth tone = dark gold body bottom

bowtieboy93 · 10-29-2007, 08:59 PM

i have the same thing but its like a loop like the support our troops sticker behind each hood spring and i havent found what they are for

z10kl · 10-29-2007, 09:47 PM

The loops I have seen on Camaros. It is used like a check mark to verify something has been checked.

ChevLoRay · 10-29-2007, 09:59 PM

M49 (I believe) is for a Turbo 400. At least it is on my truck.

Are you going to leave all these markings on your truck, or will they go away if you repaint it?

72armyswbtruck · 10-30-2007, 07:06 AM

Hey, I never really paid that much attention to those numbers before, is it true that they were used instead of build sheets?

CST*TEN in Katy · 10-31-2007, 10:53 AM

Roger0080 - Except it was 3 tone-white top, gold middle, white below the lower trim.

ChevLoRay- I looked at the option list I have, you're right. M49 is TH400. But mine is definitely a TH350 with the anle corner on the drain pan. I doubt it was swapped, I bought this truck in 1978 with 32,000 miles on it.

Are you dissin' my repaint job I did myself last year? It was less than $500 total, so I don't mind throwing stuff in the bed.

Huck · 10-31-2007, 01:03 PM

The 4T or T4 stands for the number of tires to be installed with a turbo 400. hehehehehe

weasel29gm · 10-31-2007, 01:05 PM

3-tone? Never heard that before.

CST*TEN in Katy · 11-04-2007, 09:46 AM

Wait.......... They can't be paint codes. The marks are on top of the gold firewall paint!

71 super · 11-04-2007, 02:21 PM

On my 71 super, vin was on firewall as was the paint code under the brake booster, option code was also located on front core support and model number on firewall. Under bucket on drivers side carpet was 118 in white grease pencil. There were also several markings located on framerails- CE10734 (model #)- om 4x4 KE10734 located on rear frame crossmember, r14 on bellhousing and gentleman named john signed gas tank.

10-27-2007, 02:28 PM	#1
CST*TEN in Katy Registered User Join Date: Jul 2005 Location: Katy, TX Posts: 48	Help decode the firewall? I can figure out most of the markings on the firewall. I guess some assembly plants (mine was from St. Louis) used this instead of a build sheet. CE10934 would be the model. LS9 is the engine M49 is the TH350 A/C is fairly obvious. What is the T4 and 4T on the left and right sides? It doesn't seem to correspond to anything on the glovebox sticker. Except all the RPO codes have a 4 in front of them. 4 what? There was also ome marking I found on a rear cross brace over the axle that probably designated the axle ratio, but I blasted and painted over it. Attached Images __________________ 1970 CST-10 owned it 26 years, finally back on the road after a 10 year rest. 1989 Suburban 1971 Sleekcraft 455Olds Berkeley 1992 SC400 pimp ricer

10-27-2007, 05:22 PM	#2
BACKYARD88 On the fast track to nowhere.. Join Date: May 2006 Location: Splendora, Texas Posts: 5,316	Re: Help decode the firewall? Still trying to figure this one out huh. I don't have any idea what it means but I'm going to try and find out. It's been bothering me since the meet __________________ -Mike Owen- Support the board here! 71 Chevy short fleet build thread Double D Norwood, Houston, Cecilia, Jackson, Monroe and counting

10-27-2007, 08:16 PM	#3
Longhorn Man its all about the +6 inches Join Date: Jan 2001 Location: Hilliard Ohio Posts: 2,690	Re: Help decode the firewall? Could be something like assembly line number and shift number... or something like that. No tellin.

10-28-2007, 11:40 PM	#4
roger0080 Registered User Join Date: Nov 2000 Location: Carver County, Minnesota, USA Posts: 626	Re: Help decode the firewall? Usually you see "2T" when it is a two tone paint job: white cab, colored body. Maybe for the fancier paint combo like yours, it's marked "4T" for four tone ? Haven't seen what the firewall markings are for a paint job like yours of white/dark gold/white. Maybe the "4T" is figured like this: First tone = white cab top Second tone = dark gold (hood/top color) Third tone = white side body Fourth tone = dark gold body bottom __________________ 72 Chev C-10 90% restored (former AZ truck) ... 71 Chev K-20 Cheyenne my vacation crusier... 72 Chev C-10 Now retired and striped after many faithful miles... 72 GMC 1500 Retired to the junk yard after bought new in '71...

10-29-2007, 08:59 PM	#5
bowtieboy93 Registered User Join Date: Feb 2007 Location: (Cloverdale) Surrey BC Canada Posts: 1,566	Re: Help decode the firewall? i have the same thing but its like a loop like the support our troops sticker behind each hood spring and i havent found what they are for __________________ Travis travis_moffatt@hotmail.com 1969 Chevrolet C-10 LWB, 350c.i., TH350, In Pieces. 1991 GMC Sonoma, IROCS s10 grill 1963 Ford Galaxie 351/C4

10-29-2007, 09:47 PM	#6
z10kl Registered User Join Date: Oct 2006 Location: denver nc Posts: 97	Re: Help decode the firewall? The loops I have seen on Camaros. It is used like a check mark to verify something has been checked. __________________ 70 CST Bunch of old Camaros

10-29-2007, 09:59 PM	#7
ChevLoRay Old Skool Club Join Date: Jun 2001 Location: Benton, AR "The Heart of Arkansas" Posts: 10,880	Re: Help decode the firewall? M49 (I believe) is for a Turbo 400. At least it is on my truck. Are you going to leave all these markings on your truck, or will they go away if you repaint it? __________________ Member Nr. 2770 '96 GMC Sportside; 4.3/SLT - Daily driven....constantly needs washed. '69 C-10 SWB; 350/TH400 - in limbo The older I get, the better I was.

10-30-2007, 07:06 AM	#8
72armyswbtruck Registered User Join Date: Feb 2004 Location: Idaho Posts: 4,033	Re: Help decode the firewall? Hey, I never really paid that much attention to those numbers before, is it true that they were used instead of build sheets? __________________ "Remember, They can Kill You, but they can't eat You, That's against the law!!!!!!!!!"

10-31-2007, 10:53 AM	#9
CST*TEN in Katy Registered User Join Date: Jul 2005 Location: Katy, TX Posts: 48	Re: Help decode the firewall? Roger0080 - Except it was 3 tone-white top, gold middle, white below the lower trim. ChevLoRay- I looked at the option list I have, you're right. M49 is TH400. But mine is definitely a TH350 with the anle corner on the drain pan. I doubt it was swapped, I bought this truck in 1978 with 32,000 miles on it. Are you dissin' my repaint job I did myself last year? It was less than $500 total, so I don't mind throwing stuff in the bed. __________________ 1970 CST-10 owned it 26 years, finally back on the road after a 10 year rest. 1989 Suburban 1971 Sleekcraft 455Olds Berkeley 1992 SC400 pimp ricer

10-31-2007, 01:03 PM	#10
Huck Senior Member Join Date: Jun 2001 Location: Shelbyville, KY Posts: 3,261	Re: Help decode the firewall? The 4T or T4 stands for the number of tires to be installed with a turbo 400. hehehehehe

10-31-2007, 01:05 PM	#11
weasel29gm SLOW BUT SURE,BUT CLOSER Join Date: Feb 2002 Location: eleanor wv usa Posts: 3,096	Re: Help decode the firewall? 3-tone? Never heard that before. __________________ 69 C-10, OWNED 38YRS... 350 over 30, 350 Turbo, 3:73 Posi P/S, P/B Black with red and black int. ''LOVE THESE OLD ''TRUCKS.......

11-04-2007, 09:46 AM	#12
CST*TEN in Katy Registered User Join Date: Jul 2005 Location: Katy, TX Posts: 48	Re: Help decode the firewall? Wait.......... They can't be paint codes. The marks are on top of the gold firewall paint! __________________ 1970 CST-10 owned it 26 years, finally back on the road after a 10 year rest. 1989 Suburban 1971 Sleekcraft 455Olds Berkeley 1992 SC400 pimp ricer

11-04-2007, 02:21 PM	#13
71 super Registered User Join Date: Sep 2005 Location: Canton North carolina Posts: 3,080	Re: Help decode the firewall? On my 71 super, vin was on firewall as was the paint code under the brake booster, option code was also located on front core support and model number on firewall. Under bucket on drivers side carpet was 118 in white grease pencil. There were also several markings located on framerails- CE10734 (model #)- om 4x4 KE10734 located on rear frame crossmember, r14 on bellhousing and gentleman named john signed gas tank.



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