Hey guys im currently looking at a 340 block and the casting numbers are 2780930-340-2 and then date code i believe 5-31-72. But also it has large 4's stamped on it also. My main question is what does the large 4 represent and what is the -2 after 340 stand for? Any help is good thanks guys!
340 engine decoding
- Thread starter bbizelli
- Start date
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3404speed
Ancient Decrepit Member
could have been a late 1972 car engine, but still likely to be a cast crank and lower compression pistons from the factory.
OldmanRick
Well-Known Member
I'd almost bet on it........And the possibility of a steel crank is better then 90% imo. I'm almost positive i've seen a 72' steel engines date coded after that. If i'm wrong then let the beating begin....lol.:violent1::violent1::violent1:.
From what I read the "car" build date was before april not the engine to have a forged crank.But I haven't done any first hand deep research,I was just looking around to see if my 72 cuda that was built in nov 71 had a forged or cast crank.And aren't late 72's actaully 73's as mine was built in nov.
OldmanRick
Well-Known Member
A Nov. engine build would surely be the next model year, but his is the last day of May and i believe the cut off on the car builds were in very late July. I may be wrong, but it will be cool to find out...
.This tell's the story....
Forged.....
View attachment 116.jpg
Cast.....
View attachment cast.jpg
A Nov. engine build would surely be the next model year, but his is the last day of May and i believe the cut off on the car builds were in very late July. I may be wrong, but it will be cool to find out...
Just for clarification my car was built in nov.I haven't looked for the engine build date.Now you have given me something to look at with the balancers.
OldmanRick
Well-Known Member
A Nov. engine build would surely be the next model year, but his is the last day of May and i believe the cut off on the car builds were in very late July. I may be wrong, but it will be cool to find out...
Just for clarification my car was built in nov.I haven't looked for the engine build date.Now you have given me something to look at with the balancers.
Your Cuda should definetely be forged if that's the original block. The cast 340's were used in the 73' models only as far as i know.
3404speed
Ancient Decrepit Member
I have a 72 cuda 340 with a build date of 7/09/72, and it is a cast crank numbers match.
OldmanRick
Well-Known Member
mopar410, you may be right as far as the late 72's being cast. Did a little snooping around and saw a few sites saying Apr. and later engines were cast? I give up....lol. Sometimes i wonder if certain plants didn't have more leftovers or not. Production lines in the early seventies....who knows .
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3404speed
Ancient Decrepit Member
Personally, I don't know when they switched to cast cranks, but I'm sure Chrysler would have used up their production run of forged cranks to save money...or when they ran out, they started using cast cranks...who knows?
OldmanRick
Well-Known Member
bbizelli, not trying to neglect you . If you can determine that it's in decent shape and hasn't been bored more that .030 over, it's probably a good buy regardless if it's a forged or cast crank.
. If you can determine that it's in decent shape and hasn't been bored more that .030 over, it's probably a good buy regardless if it's a forged or cast crank.
Mrmopartech
Well-Known Member
Send me this info please,mrmopartech
Well its just a bare block now and the guy has a cast and a forged crank he will be giving me with it. Its standard bore also all for 250 which i thought was a pretty good deal. Ill upload the pictures he sent me so you can see them.
With original main caps that's a good deal with the extra stuff.
Not that it matters what year the block is, they are all the basic piece. If you post up the numbers from the front of the block it will nail it down. If it's a 72 the first letter in that sequence should be a "H", 1973 will be a "J"
It's a late 72 or 1973 model year engine, that's for sure.
Not that it matters what year the block is, they are all the basic piece. If you post up the numbers from the front of the block it will nail it down. If it's a 72 the first letter in that sequence should be a "H", 1973 will be a "J"
It's a late 72 or 1973 model year engine, that's for sure.
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