Help with 340 decoding

[Troy]

I'm waaaaay out of my element on this one and, so far, the information I've found on the internet is far from conclusive. Seller claims it's from a 71 Challenger based on GG book.

Casting #: 2780930-340-8
There are at least two large '4' castings
Casting Date: 6-17-71
Arrow pointing at 3:00
Arrow pointing to 'D' (on 'D'/'N')
VIN Stamp hard to read but looks like "2A121**8"
Stamping on front pad: "HM 340R 720142"
Has a steel crank drilled for a 4-speed.
Intake casting number matches 1972 340 and it has a trashed Thermoquad.
Color is dark blue - never been painted that I can tell.

Looks like a very late 71 casting date for an early 72 Lynch Road car. I have no idea how to decode that last part on the front stamp. What was manufactured at that plant?

I'm definitely lost on the heads:
one has "3418915H" casting with 2590 date
other has no discernible part # but has "34 80 6"(?) with a large 'D' in the same spot and 2880 date
Both say "AAWJ"

Looks like it's never been apart. Pulled it out of a pickup so the pan and motor mounts are incorrect for a car. Any ideas on value?

Troy

[69CoronetRT]

I'm waaaaay out of my element on this one and, so far, the information I've found on the internet is far from conclusive. Seller claims it's from a 71 Challenger based on GG book.

VIN Stamp hard to read but looks like "2A121**8"
Stamping on front pad: "HM 340R 720142"H= Built for 1972 model car. M = assembled at Mound road plant. 340 = CID. R= regular fuel. There should be a '3' after the R and before the 7. If the correct series is 3720 = assembled Oct 4th 1971 making 142 = the 142nd engine assembled that day

Looks like a very late 71 casting date for an early 72 Lynch Road car. I agree

72 Lynch Road built Chargers and Coronets so it looks like it's out of a 72 Charger Rallye.

[Troy]

Thanks!

The stamped pad is very light. I assumed there should be more numbers as there's a good sized space after the "340R". Does it seem odd that the heads are dated about 9 months before the engine cast date and over a year prior to the assembly date?

I guess I should see if anyone owns the car now but, from the story I got I'd say it's long gone. This group of guys has been parting cars for a very long time and sounds like some of them weren't too bad. Of course, even I remember a time where most of these cars weren't worth much at all (my first Challenger cost me $300). This engine was pulled out of a truck many years ago so who knows how long it had been separated from the car.

Troy

[John_Kunkel]

I assumed there should be more numbers as there's a good sized space after the "340R".

Yeah, the numbers posted don't make sense. The 0142 is probably the sequence number and the missing digits before the 72 could be 36, 37, 38 or 39 for the '72 model year build date.

[Troy]

Hmmm, "3672 0142" seems likely. That would be August 17 (2 months after casting). I checked again last night and I've got the pad pretty clean but still can't make out any other numbers. How fast were they cranking out cars at Lynch Road? The first two in the VIN sequence are definitely "12" so that would put it around 20,000 cars into production (if I did the math right).

Troy

[69CoronetRT]

Hmmm, "3672 0142" seems likely. That would be August 17 (2 months after casting). I checked again last night and I've got the pad pretty clean but still can't make out any other numbers. How fast were they cranking out cars at Lynch Road? The first two in the VIN sequence are definitely "12" so that would put it around 20,000 cars into production (if I did the math right).

Car 2A127*** has an SPD of Oct 15th so 120 would be early -mid Oct making an Oct 4th assembly quite possible for a 120*** VIN car.

[Troy]

Cool, thanks.

So, now that we've determined what it is... the 64,000 question becomes: what do I do with it? The seller listed it as "70-71 340 with X or J heads" (clear as mud right?). When I went to look at it I could barely see the stampings and couldn't see the month part of the casting date. Based on the decoding information I had taken with me, I incorrectly assumed it was a 71 and purchased it (for a 70-71 price too). That's my fault for getting excited without verifying all the information. I planned to put it in my 1970 Challenger 340 (A66) car even though it isn't "date correct". Obviously the heads are the wrong casting (but you can't tell from outside can you?) but it is a steel crank and does have reasonably good heads. I'm bummed that the carb, motor mounts, oil pan, and exhaust manifolds won't work and I know the intake isn't right for a 70 so the it-has-a-bunch-of-parts-that-I-have-to-buy-any-way justification doesn't hold up so well. The steel crank and balancer are a big relief (about the only positive so far in this ordeal). If it ends up being stock bore that would be a plus.

If I keep it I'm thinking that it will at least look correct for the most part. After a rebuild the cam and compression ratio would be corrected, it would be painted the right color, and I'd likely use an LD340 intake and aftermarket carb so those problems are mostly solved. However, if I have to do all that is it worth trying to find a correct engine/block to begin with? At least if I get a block I could scavenge parts from this engine and sell the 72 block. The big issue there is my car is an early build and I haven't yet run across anything with the right dates since I've owned the car.

Or, I could sell this thing and keep looking or follow my current plan and spend the money on it. I had given up on finding a 340 so I already started building a late model 5.9 Magnum. It should end up with more power for about 1/2 the cost of the 340 and I get the benefits of aluminum heads, a lighter rotating assembly, and roller cam. No, it doesn't quite look "stock" but I drive more than I show (about 18k per year on my classics) and it would be easy to swap later. The rub with that is that my car is reasonably rare (7,500 or so A66 cars) and it's a high impact color (Sublime) with A/C (definitely odd). In those circumstances I like to stick close to stock. I think I just make things more difficult for myself. I should only buy base model cars that are missing their drive trains.

Any one want to buy the car? That would put an end to my struggles (well, in this area at least).

Troy

[69CoronetRT]

"Incorrect" will always be 'incorrect' whether it's a date coded block or this one.

If it's a driver who cares about the block?

Most people will never know or care about the date on the block.
IMHO most people that do care about the date on the block would still rather see a 340 in an A66 car than the new engine.

IMHO...rebuild the 72 block to 70 visual specs and enjoy the car.