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A31 Date code.

WISCOPAR

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Hey guys,

I've got a 1970 GTX. I pulled the 1972 engine out of the car and swapped it into my drag dart. The engine needs race gas, and it tends to get hot on summer cruises. At any rate, I'm now on the hunt for a correct date coded 440. My fender tag states "A31" for a date code. I understand this to be Halloween day. My question: Is this Halloween day 1969, or 1970?

Any tips, pointers and suggestions on getting the date date coded 440 will be greatly appreciated.

70 GTX.jpg 6.jpg 7.jpg
 
Hey guys,

I've got a 1970 GTX. I pulled the 1972 engine out of the car and swapped it into my drag dart. The engine needs race gas, and it tends to get hot on summer cruises. At any rate, I'm now on the hunt for a correct date coded 440. My fender tag states "A31" for a date code. I understand this to be Halloween day. My question: Is this Halloween day 1969, or 1970?

Any tips, pointers and suggestions on getting the date date coded 440 will be greatly appreciated.

View attachment 780897 View attachment 780898 View attachment 780899
The casting should be date coded for 69 or 70 since your car was a end of year build, early builds would have mostly 69 castings. Mopar, after casting would put blocks aside for seasoning (about4 to 6 months) before doing the machine work, so the car should not have a date coded block preceding the model year (71 and later) unless it's a warranty block/engine replacement.
 
OK. So you're saying the car was built on Halloween day in 1969? Any insight on the casting dates or stamping information I'm looking for to put a period correct 440 in the car?
 
The casting should be date coded for 69 or 70 since your car was a end of year build, early builds would have mostly 69 castings. Mopar, after casting would put blocks aside for seasoning (about4 to 6 months) before doing the machine work, so the car should not have a date coded block preceding the model year (71 and later) unless it's a warranty block/engine replacement.


So you're saying that the car was built late, meaning Halloween day of 1970?
 
OK. So you're saying the car was built on Halloween day in 1969? Any insight on the casting dates or stamping information I'm looking for to put a period correct 440 in the car?
No, built 10-31-70. So the casting can be 69 or 70
I stand corrected, don't know what I was thinking. 69 mfg. date is correct
 
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1970 model built 10/31/69 ........ you're looking for an F440 HP assembled late september - mid october . would appear correct from the top but 70 (69 and up) blocks have a VIN stamped down low
 
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By October 1970, 1971 model cars had been on the showroom floor for a month. They started 71 production in august. They sure weren't making 70s in october.
Yes, your car was built on halloween, 1969. A 1970 casting date would mean they cast the block two or more months after the car was built. Unlikely, dont you think?
 
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Looking for a mid to late 69 block probably between August and early October sometime. Yes you car was built on October 31, 1969.
 
I assume if a 440 is decked, the stampings get wiped....... so almost any decked 440 could pass visually from the top......... stamp it F440 HP 10 02 if you wish ........ some may frown on this but it wouldn't be a matching block anyway due to the vin

not a machinist, but pretty sure I'm correct
 
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I assume if a 440 is decked, the stampings get wiped....... so almost any decked 440 could pass visually from the top......... stamp it F440 HP 10 02 if you wish ........ some may frown on this but it wouldn't be a matching block anyway due to the vin

not a machinist, but pretty sure I'm correct
Eldubb, i think you're mistaken, a 440 has a seperate pad in front of the valley cover with tbe numbers, machining the deck wont touch (unlike a chevy). I'm not sure about a b-engine low deck, their numbers are in a different place, i dont know if decking removes them.
Image is 63 426 wedge block, typical of rb casting.

20181125_120156.jpg
 
Your motor was built on Halloween, and this thread sure is scary!
 
Eldubb, i think you're mistaken, a 440 has a seperate pad in front of the valley cover with tbe numbers, machining the deck wont touch (unlike a chevy). I'm not sure about a b-engine low deck, their numbers are in a different place, i dont know if decking removes them.
Image is 63 426 wedge block, typical of rb casting.

View attachment 780992
yeah...... thats what i wondered about....... couldn't that be cut also as a way of fitting the intake?

that being said, i have a date correct non hp block for my gtx...... i painted the pad a little heavy and it made it almost impossible to tell
 
No, there is no machining procedure that will get anywhere near that pad. The only reason to work on that pad is to change the numbers. The matching vin numbers are on a pad down near the oil pan rail. Changing numbers on the number pad will only make it appear to be date correct.
 
stole this partial quote from another thread.....post 16

Since the manifold doesn't seal to the block, it isn't necessary to mill the valley rails, but I do to clean them up and for head/valley alignment. I usually cut about 0.012" to 0.015" for a general head/block cleanup

https://www.forbbodiesonly.com/moparforum/threads/cylinder-head-questions.173598/

the pad is just an extension of the valley rail.... I wouldn't think it would take much to remove the stamping..... it seems to me. decking the block shortens the rails anyway, and some would need to be removed....

disclaimer: I'm no machinist

20190610_164159.jpg
 
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