Engine Identification - The 1947 - Present Chevrolet & GMC Truck Message Board Network

kecah04 · 09-27-2002, 06:10 AM

I just purchesed a 1970 1/2 ton. I do know that the original engine was an L6. It now has a V-8. Is there some way to use the engine serial number to ID the engine? IE what year and displacement it is? thanks.

No3Fan4Ever · 09-27-2002, 07:30 AM

You can find the engine ID pad located on the passenger side of the engine block just in front of the cylinder head. There are some good engine decorder programs at some links on the main page like American Classic Trucks and Year One; also some at chevelles.com
Tim

adamls · 09-27-2002, 11:09 AM

Once you find the ID numbers take a look at www.moretec.com. They have a pretty extensive database of casting numbers for head and blocks.

**COBALT** · 09-27-2002, 01:34 PM

Yeah, there's two numbers you need. Each is used to narrow down the exact engine you have.

First, is the casting number that's located behind the driver's side head on the transmission flange - way back in the back facing up. Since it's sort of a flat surface it collects oil, grease, and other garbage. You may need to use a shaving mirror and a flashlight to see the number - ESPECIALLY if you have power brakes (that damn booster is in the way).

Second, the stamped-in number that No3Fan4Ever mentioned. Since there are several blocks for different applications that have the same casting number you'll need this number to narrow the choices down. There should be a flat area in front of the passenger side head. It will be stamped into the block rather than raised letters like a casting number, so you might need to scrub it with some brake cleaner or something. What you need off of there is the suffix of the code (the rest is the actual date code). The suffix is generally a 2 or 3 character ID, like "CRL" or something similar.

Good luck...

No3Fan4Ever · 09-29-2002, 10:08 AM

That web site for the engine casting numbers is actually
www.mortec.com and boy

do they have a plethora (that's a Jayski favorite saying) of information available about
the various casting numbers
Tim

adamls · 09-29-2002, 06:15 PM

Sorry, That is what I get for not using copy/paste.

09-27-2002, 06:10 AM	#1
kecah04 Registered User Join Date: Sep 2002 Location: Davenprort, Iowa Posts: 18	Engine Identification I just purchesed a 1970 1/2 ton. I do know that the original engine was an L6. It now has a V-8. Is there some way to use the engine serial number to ID the engine? IE what year and displacement it is? thanks.

09-27-2002, 07:30 AM	#2
No3Fan4Ever Running on empty Join Date: Aug 2002 Location: Roanoke, Virginia Posts: 1,033	You can find the engine ID pad located on the passenger side of the engine block just in front of the cylinder head. There are some good engine decorder programs at some links on the main page like American Classic Trucks and Year One; also some at chevelles.com Tim __________________ _____________________________________________ 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

09-27-2002, 11:09 AM	#3
adamls Gotta Startem Early Join Date: Oct 2001 Location: Amarillo, TX, USA Posts: 364	Once you find the ID numbers take a look at www.moretec.com. They have a pretty extensive database of casting numbers for head and blocks. __________________ 67 SWB In Progress, one piece at a time, maybe 3 years I will be finished

09-27-2002, 01:34 PM	#4
COBALT Senior Member Join Date: Sep 2001 Location: Seattle, WA, USA Posts: 5,817	Yeah, there's two numbers you need. Each is used to narrow down the exact engine you have. First, is the casting number that's located behind the driver's side head on the transmission flange - way back in the back facing up. Since it's sort of a flat surface it collects oil, grease, and other garbage. You may need to use a shaving mirror and a flashlight to see the number - ESPECIALLY if you have power brakes (that damn booster is in the way). Second, the stamped-in number that No3Fan4Ever mentioned. Since there are several blocks for different applications that have the same casting number you'll need this number to narrow the choices down. There should be a flat area in front of the passenger side head. It will be stamped into the block rather than raised letters like a casting number, so you might need to scrub it with some brake cleaner or something. What you need off of there is the suffix of the code (the rest is the actual date code). The suffix is generally a 2 or 3 character ID, like "CRL" or something similar. Good luck... __________________ '69 3/4 ton C20 2wd-350ci/TH400 '69 3/4 ton Custom 20 2wd-350ci/4sp Manual '99 2wd 5.7 Chevy Tahoe Seattle, WA.

09-29-2002, 10:08 AM	#5
No3Fan4Ever Running on empty Join Date: Aug 2002 Location: Roanoke, Virginia Posts: 1,033	That web site for the engine casting numbers is actually www.mortec.com and boy do they have a plethora (that's a Jayski favorite saying) of information available about the various casting numbers Tim __________________ _____________________________________________ 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

09-29-2002, 06:15 PM	#6
adamls Gotta Startem Early Join Date: Oct 2001 Location: Amarillo, TX, USA Posts: 364	Sorry, That is what I get for not using copy/paste. __________________ 67 SWB In Progress, one piece at a time, maybe 3 years I will be finished

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