Need help with this 340 block id.

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CudaFish1968

CudaFish1968

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I have had this engine for 20 years sitting, you know finally getting round to it.
The stamping on the block below the head has been stamped twice. I do not know what it means. I think I have a pic of the vin not sure, it appears to be a 8 or 9 -24- 71.
Can ya'll help?
Thanks
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With the "H" in the double stamp area would indicate that it was installed in a '72. That's all I got!
 
1973 motor according to the vin on the block 3B277951 casting date 9-24-72? which is for '73 model year.
 
The two 10k calendar #'s look to be Feb 72' and Sept 72'. What's the balancer look like? Probably the larger for a cast crank, especially with the 3B on the vin. Likely a late 72' build.

That said, what a mess for stampings, thanks Ma ... :)
 
3B277951, 1973 car assembly, Hamtramck built (pretty sure, didn't verify, but that's easily done) and a fairly late model year production.
 
My best guess is the block was cast in Aug. or Sept. of 1971. The block was assembled in July of 1972. And was put in a 1973 automobile. And would have left the factory with a cast crank.
 
OldmanRick said:
The two 10k calendar #'s look to be Feb 72' and Sept 72'. What's the balancer look like? Probably the larger for a cast crank, especially with the 3B on the vin. Likely a late 72' build.

That said, what a mess for stampings, thanks Ma ... :)
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Wow, ya'll are spot on, thanks for the information. This morning I took a partial pic of the balancer and the tale tale shape.... yep a cast crank balancer. I thought all these years it to be a forged steel crank engine.
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After February 10th of 72, all 340 motors were cast crank.

oops, corrected the misinformation.
 
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From what I've been able to determine, it was right around Apr 1st 1972 that the change was made from forged to cast.
 
As those stampings under the head both look factory to me, could this be a engine that failed a test before it was designated a vehicle and then some how founds it's way back into the production line months later? Seeing only one Vin stamp, just speculating. Don't see any of the skull and cross bone markings :). But if it was mine, i think i'd do some measurement checking on teardown for some odd bearing or lifter numbers. I'm just saying this out of curiosity. What do you guys think?
 
33IMP said:
3B277951, 1973 car assembly, Hamtramck built (pretty sure, didn't verify, but that's easily done) and a fairly late model year production.
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The 9th month '72 year is an early to mid year engine, not late.
 
OldmanRick said:
As those stampings under the head both look factory to me, could this be a engine that failed a test before it was designated a vehicle and then some how founds it's way back into the production line months later? Seeing only one Vin stamp, just speculating. Don't see any of the skull and cross bone markings :). But if it was mine, i think i'd do some measurement checking on teardown for some odd bearing or lifter numbers. I'm just saying this out of curiosity. What do you guys think?
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After having it for 20 years along with a set of x heads not doing anything with them, I have been thinking about selling them.
Getting older is not fun and I don't see another build in my future. I do plan on tearing into the engine to measure bore, crank etc to know what it is.
Thanks for all the help.
 
33IMP said:
Agree. I was referring to the 277951 for the CAR assembly. I think that's probably some where around February.
My 277xxx b-body, was built in May.
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ah, my 305604 was built in late Feb, '69. The body stamp (located on the trunk rail) is Jan 69
 
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