Is it really a factory big block truck? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

Troy pfeiffer · 08-14-2008, 11:54 PM

I just bought a 1968 gmc 910 and it is suppose to be an origanal 396 big block truck, it was also suppose to have a full posi rear end but ive come to discover its not its an open diff and its blown up so now im wondering if the motors origanal!! long story short just wondering if anyone can tell me if there is a way to find out for sure what motor it had from factory???

1971c20 · 08-15-2008, 12:02 AM

the vin should say i think, there is a vin id on the forum page on the left.

Troy pfeiffer · 08-15-2008, 12:06 AM

I actually tried that but the decoder seems to be for chevs? not sure if its for gms also because the decoder says the second digit should actually be a letter and mine is a number 9 so thats got me really confused!!!

*ksjh1316* · 08-15-2008, 12:35 AM

LMC catalog has a great decoder on their website in their online catalog. Also check the SPID label in the glove box if it is still there

sameyrasmea72 · 08-15-2008, 01:12 AM

The vin Is E= v-8 S=v-6. It does not tell what size the engine it came with.

68caliRat · 08-15-2008, 02:05 AM

it is possible that the truck came with a 396, mine did, and it's the stock motor..

JimKshortstep4x4 · 08-15-2008, 05:22 AM

The suffix code on the right hand front of the engine block can be decoded to determine what the engine was in originally.

Jim

Longhorn Man · 08-15-2008, 05:48 AM

look for the reamins od STOCK daul exhaust (Hangars)
Look for a heat shield low on the passenger side fire wall
Look for the correct remote power steering reservoir
Look for a factory installed high hump tranny floor
Look for the build sheet

Longhorn Man · 08-15-2008, 06:27 AM

Another indication of originality, but certinaly not proof in one direction or the other, if it has a long water pump and acc brackets it is more likely to be out of a car or a 73 & up truck. Also the motor mount style and the motor mount stand style... exhaust manifolds too.
Are you able to post photos of all this stuff?

GMC vins are not the same as chevy VINs, and as far as I know, there is no acurate decodor on line. We have a few ppl here that can read them however. If you want to post all but the last 5 digits, we'll take a look.
However, the VIN will not tell us if it is a big block truck... only if it is a V-8, inline 6, or V-6 truck.

**special-K** · 08-15-2008, 07:31 AM

Is it a 3.08 rear?Look for evidence of factory dual exhaust.

No3Fan4Ever · 08-15-2008, 07:42 AM

GMC Pauls has a vin decoder

http://www.gmcpauls.com/67-72_gmc.htm

Ozark Tim · 08-15-2008, 09:52 AM

Do you have the original Protecto plate?
If so the code to the original engine, trans, and rear diff are stamped on this plate which was used for warranty reasons and kept with the owners manual usually.
Check those #'s against the #'s on the block by the water pump and see if they match.
Typically the motor code will be be something like V0608AB or something along those lines.
OT

Troy pfeiffer · 08-15-2008, 11:04 AM

Thanks fellas this all this should send me in the right direction!! unfortunately the guy that i bought the truck from wasnt the best mechanic and he has done some crude work! i its all fixable but as far as exhaust hangers from the origanal dual exhaust im affraid there long gone

He also had attemted to make his own headers in the truck so the motor mounts wrer changed to small block mounts ect so i have alot of work ahead of me but it should be worth it!! anyways thanks again !!

08-14-2008, 11:54 PM	#1
Troy pfeiffer Registered User Join Date: Aug 2008 Location: Calgary Alberta Canada Posts: 26	Is it really a factory big block truck? I just bought a 1968 gmc 910 and it is suppose to be an origanal 396 big block truck, it was also suppose to have a full posi rear end but ive come to discover its not its an open diff and its blown up so now im wondering if the motors origanal!! long story short just wondering if anyone can tell me if there is a way to find out for sure what motor it had from factory???

08-15-2008, 12:02 AM	#2
1971c20 Registered User Join Date: Jul 2008 Location: Vancouver Washin-tin Posts: 168	Re: Is it really a factory big block truck? the vin should say i think, there is a vin id on the forum page on the left. Last edited by 1971c20; 08-15-2008 at 06:12 AM.

08-15-2008, 12:06 AM	#3
Troy pfeiffer Registered User Join Date: Aug 2008 Location: Calgary Alberta Canada Posts: 26	Re: Is it really a factory big block truck? I actually tried that but the decoder seems to be for chevs? not sure if its for gms also because the decoder says the second digit should actually be a letter and mine is a number 9 so thats got me really confused!!! Last edited by Troy pfeiffer; 08-15-2008 at 12:06 AM. Reason: miss spoke?

08-15-2008, 12:35 AM	#4
ksjh1316 Account Suspended Join Date: Jul 2007 Location: Wichita KS Posts: 1,599	Re: Is it really a factory big block truck? LMC catalog has a great decoder on their website in their online catalog. Also check the SPID label in the glove box if it is still there

08-15-2008, 01:12 AM	#5
sameyrasmea72 Senior Member Join Date: Aug 2003 Location: Lubbock, Texas Posts: 2,443	Re: Is it really a factory big block truck? The vin Is E= v-8 S=v-6. It does not tell what size the engine it came with. __________________ 72 Cheyenne Super 80 Silverado Blazer 2wd

08-15-2008, 02:05 AM	#6
68caliRat Need a bigger hammer.. Join Date: Feb 2007 Location: Escondido,CA. Posts: 280	Re: Is it really a factory big block truck? it is possible that the truck came with a 396, mine did, and it's the stock motor.. __________________ 1968 GMC 3/4 LWB fleetside Custom Camper 2018 Silverado High Country 2500HD Duramax 4X4

08-15-2008, 05:22 AM	#7
JimKshortstep4x4 Senior Member Join Date: Jul 2001 Location: Muskegon,MI,USA Posts: 6,026	Re: Is it really a factory big block truck? The suffix code on the right hand front of the engine block can be decoded to determine what the engine was in originally. Jim __________________ 1971 Shortbox step side 4x4, 350 sbc, 3:07 rear end 1965 Impala SS 400 sbc, Muncie rock crusher 1966 Impala SS 396 bbc, TH 400 1969 El Camino, 350 sbc, TH 350 1971 Snowplow built on a Blazer frame 1972 GMC Short bed, stepside, TH 400, 427 BBC

08-15-2008, 05:48 AM	#8
Longhorn Man its all about the +6 inches Join Date: Jan 2001 Location: Hilliard Ohio Posts: 2,690	Re: Is it really a factory big block truck? look for the reamins od STOCK daul exhaust (Hangars) Look for a heat shield low on the passenger side fire wall Look for the correct remote power steering reservoir Look for a factory installed high hump tranny floor Look for the build sheet

08-15-2008, 06:27 AM	#9
Longhorn Man its all about the +6 inches Join Date: Jan 2001 Location: Hilliard Ohio Posts: 2,690	Re: Is it really a factory big block truck? Another indication of originality, but certinaly not proof in one direction or the other, if it has a long water pump and acc brackets it is more likely to be out of a car or a 73 & up truck. Also the motor mount style and the motor mount stand style... exhaust manifolds too. Are you able to post photos of all this stuff? GMC vins are not the same as chevy VINs, and as far as I know, there is no acurate decodor on line. We have a few ppl here that can read them however. If you want to post all but the last 5 digits, we'll take a look. However, the VIN will not tell us if it is a big block truck... only if it is a V-8, inline 6, or V-6 truck.

08-15-2008, 07:31 AM	#10
special-K Special Order Join Date: Nov 2004 Location: Mt Airy, MD Posts: 85,851	Re: Is it really a factory big block truck? Is it a 3.08 rear?Look for evidence of factory dual exhaust. __________________ "BUILDING A BETTER WAY TO SERVE THE USA"......67/72......"The New Breed" GMC '67 C1500 Wideside Super Custom SWB: 327/M22/3.42 posi.........."The '67" (project) GMC '72 K2500 Wideside Sierra Custom Camper: 350/TH350/4.10 Power-Lok..."The '72" (rolling) Tim "Don't call me a redneck. I'm a rough cut country gentleman" R.I.P. ~ East Side Low Life ~ El Jay ~ 72BLUZ ~ Fasteddie69 ~ Ron586 ~ 67ChevyRedneck ~ Grumpy Old Man ~

08-15-2008, 07:42 AM	#11
No3Fan4Ever Running on empty Join Date: Aug 2002 Location: Roanoke, Virginia Posts: 1,033	Re: Is it really a factory big block truck? GMC Pauls has a vin decoder http://www.gmcpauls.com/67-72_gmc.htm __________________ _____________________________________________ Tim We have two rules here at the Rock. Rule #1: No writing on the walls. Rule#2: Obey all rules 70 GMC Sierra Grande "Custom Camper" Longhorn 402 Big Block TH400 PS PB factory AC Posi; 94 Bronco XLT 302, auto;worn out daily driver

08-15-2008, 09:52 AM	#12
Ozark Tim Registered User Join Date: Aug 2004 Location: Oakville, MO Posts: 1,018	Re: Is it really a factory big block truck? Do you have the original Protecto plate? If so the code to the original engine, trans, and rear diff are stamped on this plate which was used for warranty reasons and kept with the owners manual usually. Check those #'s against the #'s on the block by the water pump and see if they match. Typically the motor code will be be something like V0608AB or something along those lines. OT

08-15-2008, 11:04 AM	#13
Troy pfeiffer Registered User Join Date: Aug 2008 Location: Calgary Alberta Canada Posts: 26	Re: Is it really a factory big block truck? Thanks fellas this all this should send me in the right direction!! unfortunately the guy that i bought the truck from wasnt the best mechanic and he has done some crude work! i its all fixable but as far as exhaust hangers from the origanal dual exhaust im affraid there long gone He also had attemted to make his own headers in the truck so the motor mounts wrer changed to small block mounts ect so i have alot of work ahead of me but it should be worth it!! anyways thanks again !!

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