GM BB replacement in 1972? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

**JQ-72** · 05-22-2010, 09:39 AM

I just got a '72 402 that came out of an original 2-owner truck. I was checking the block suffix code and there is nothing there! You can barely make out the bottom half of one number, but that's all. The pad looks to have never been tampered with - very smooth. The casting number on the back is 3999290 and is dated late 1973. Different websites decipher this casting number as 70-72 truck and 70-72 full size car. However the heads, intake and water pump are all dated 12-71 and are truck correct. Would GM have done this in '73-'74 (warranty) if the original '72 motor broke?

Joshua

**D.PASSMORE** · 05-22-2010, 09:47 AM

I think some BB codes are above timing chain cover and if was on the tab in front the pass. side head, the block could have been decked on a rebuild. Some thoughts...

**JQ-72** · 05-22-2010, 11:24 AM

Ah-ha. I didn't think about that. That's probably the case. Thanks.
JQ

factorystock · 05-22-2010, 12:48 PM

Some GMC engines do not have engine codes stamped.

**71blksuper4x4** · 05-22-2010, 02:50 PM

Josh, back then, GM did warranty engines for a year from when the vehicle sold off the lot. It was quite common to see muscle cars with CE (crate engine) coded engines or even blocks of later dates. Mostly because of blowing them up under the warranty. That is one reason numbers matching muscle cars cost so much. A lot of them were blown within the first 20,000 miles. This would be one of the first cases I have seen hearing about a truck with a warranty engine but I am very certain that it could have happened. Most trucks back then weren't pushed like the muscle cars, but a minor engine problem could have caused replacement under warranty. Trevor

05-22-2010, 09:39 AM	#1
JQ-72 Senior Member Join Date: Feb 2001 Location: Killen, Alabama USA Posts: 3,589	GM BB replacement in 1972? I just got a '72 402 that came out of an original 2-owner truck. I was checking the block suffix code and there is nothing there! You can barely make out the bottom half of one number, but that's all. The pad looks to have never been tampered with - very smooth. The casting number on the back is 3999290 and is dated late 1973. Different websites decipher this casting number as 70-72 truck and 70-72 full size car. However the heads, intake and water pump are all dated 12-71 and are truck correct. Would GM have done this in '73-'74 (warranty) if the original '72 motor broke? Joshua __________________ 72 Cheyenne Super swb. Factory 402/400,tach,posi,AM/FM, A/C. Adding cruise, 8-track 72 Cheyenne Super swb. 350/350 A/C, bucket seats 72 Cheyenne swb. Factory 402/400, tilt, posi, A/C 72 Cheyenne Super K-10. 350/4 spd., posi. 72 Suburban 350/350 tilt, tach, AM/FM, A/C, luggage rack 72 GMC Sierra lwb. 350/350, A/C. medium green/olive interior

05-22-2010, 09:47 AM	#2
D.PASSMORE One of the First Join Date: Jan 2000 Location: St. Augustine,FL. Posts: 4,054	Re: GM BB replacement in 1972? I think some BB codes are above timing chain cover and if was on the tab in front the pass. side head, the block could have been decked on a rebuild. Some thoughts... __________________ DAVID PASSMORE ST AUGUSTINE ,FL ZIP 32084 '71 SWB K/10 CUSTOM DELUXE (Chili) '72 BLAZER K/5 Muscle Truck (Mule) '72 LWB K/20 CHEYENNE (Blackie)

05-22-2010, 11:24 AM	#3
JQ-72 Senior Member Join Date: Feb 2001 Location: Killen, Alabama USA Posts: 3,589	Re: GM BB replacement in 1972? Ah-ha. I didn't think about that. That's probably the case. Thanks. JQ __________________ 72 Cheyenne Super swb. Factory 402/400,tach,posi,AM/FM, A/C. Adding cruise, 8-track 72 Cheyenne Super swb. 350/350 A/C, bucket seats 72 Cheyenne swb. Factory 402/400, tilt, posi, A/C 72 Cheyenne Super K-10. 350/4 spd., posi. 72 Suburban 350/350 tilt, tach, AM/FM, A/C, luggage rack 72 GMC Sierra lwb. 350/350, A/C. medium green/olive interior

05-22-2010, 12:48 PM	#4
factorystock Registered User Join Date: Feb 2007 Location: west coast Posts: 3,377	Re: GM BB replacement in 1972? Some GMC engines do not have engine codes stamped.

05-22-2010, 02:50 PM	#5
71blksuper4x4 SWB 4x4 Collector Join Date: Jun 2001 Location: Osage City, KS Posts: 5,155	Re: GM BB replacement in 1972? Josh, back then, GM did warranty engines for a year from when the vehicle sold off the lot. It was quite common to see muscle cars with CE (crate engine) coded engines or even blocks of later dates. Mostly because of blowing them up under the warranty. That is one reason numbers matching muscle cars cost so much. A lot of them were blown within the first 20,000 miles. This would be one of the first cases I have seen hearing about a truck with a warranty engine but I am very certain that it could have happened. Most trucks back then weren't pushed like the muscle cars, but a minor engine problem could have caused replacement under warranty. Trevor __________________ TREVOR 1970 CST swb 4x4 (speedwarning,cruise,tilt,tach,8track, original red shoulder belts,tow hooks) 1972 Jimmy (soon to be Hickey cloned) 1971 Cheyenne Super 4x4 swb (tilt,tach,buckets, original blue shoulder belts,am/fm,cruise,tow hooks, dealer 8 track) 1972 Cheyenne Super K20 4x4 Custom Camper (tilt, tach, am/fm, tow hooks, bed toolbox, aux gas tank 1972 Cheyenne Super Crew Cab K30 4x4 Duramax, Allison, np205, buckets, tow hooks (CURRENT PROJECT) http://67-72chevytrucks.com/vboard/s...d.php?t=624819 1989 V3500 Crew Cab (454tbi, NV4500, np205) 1970 Chevelle SS (LS5 454,th400,8track,buckets,tach) :2004 Jeep Wrangler Rubicon (daily driver) WTB: 1968-70 Cruise Control Lever



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