Hello: I am in the market for a date correct 1966 273 motor. I have found a couple early casting date motors, August and September 1965 that have heads that have casting numbers 2465315. That number is for a 1965 motor. Did Chrysler put 1965 casting code heads on some early 1966 motors? I thought that the 1965 heads were not interchangeable with 1966 motors. I would appreciate any help on this. Thank you. Bob
273 casting number question
- Thread starter rdoylejr
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Hey Bob, The 315 heads are the 64/5 castings and the intake bolts are smaller and at a different angle than the 66 and newer heads. I don't know how abruptly Mopar quit using one number head and started using another. It would be possible for them to take the last batch of 315 heads and machine them with the larger bolt holes at a different angle. Early 273 heads should be casting #2536178 and the later 273 heads are #2658234. I don't see any difference in the block casting number #2465330. That number is listed for 1964-1966. tmm
A quick look under the left front head where it meets the block will reveal a stamping pad and the year confirmation for the 66 273 block! You are looking for a capital "B"stamped there, indicating a 66 year block! Casting dates are a general parameter, but the B stamp indicates that it is built for a 66 car!
Pic of the area with a B stamp, from a 66 motor from a Cuda! Stamp says B273 4-12, indicating a 1966 273 with an assembly date of April 12th!
Incidentally, the motor I pictured has a casting date of 3-3-66...March 3rd 1966!! Interested? PM me!! Geof
Pic of the area with a B stamp, from a 66 motor from a Cuda! Stamp says B273 4-12, indicating a 1966 273 with an assembly date of April 12th!
Incidentally, the motor I pictured has a casting date of 3-3-66...March 3rd 1966!! Interested? PM me!! Geof
That's a good thing. If your casting date on your block and manufacturing date on the engine are within 1-2 months, then you had a good "first time through" engine and block. Not repair or torn down and recycled again.... :cheers:
Ahh, but in the craziest turn of events, this motor has a 2658920 head on the drivers side, and a 2465315 head on the passenger side, although neither head looks to have ever been off!! Hmm!!!.....
2465315= 64-65 273 head
2658920= 67 273 head
But the craziest part is that the block casting is 2806030, which decodes as a 67-74 318, but is clearly stamped B273 4-12 and the casting date is 3-3-66!!
Late casting?? Mutt motor leftover parts?? I'm now stumped!!!...
I had 2 different heads too but I had one rod bearing which was a decade newer. I'll bet mune lost a rod bearing and the piston kissed the head. tmm
Save the original head gaskets. I like to measure them to see what volume they were. Thickness and diameter for compression calculations...
When they were doing the change over to 318, they may have pulled ahead some of the mold tooling and mixed and matched the cores until they were all brought up to the lastest changes. - rotating their molds to be modified.
It does happen.
Does the 2465315 head have 5/16 intake bolts or 3/8 intake bolts?
The 315 head should have the early intake bolts unless a few of the earliest 66's were built with 65 parts. I haven't heard or seen it but anything is possible. I would think the leftover heads would be transferred to Mopar Parts when the change over occurred.
Both sides are 3/8" bolts! No sign of any changes to the intake bolt angle or anything!! Hmm.....
I have a 66 block that will be going together this winter, that has one each of the casting numbers as well, but the bolt angles on both are correct for the 66 up la intakes.
Mike, the strange thing is that this is not an early 66 motor! By any account, an assembly date of April 12th is very late in the model year, and very close to a complete change of body style, and the introduction of the 318!! I know the 273 continued on through 69, but its an oddball for sure! Not surprised considering Ma's business as usual practice, but odd just the same!! Geof
That is a strange combo for sure. I wonder if the 315 head was a un-machined casting and was machined to 920 specs. Was the block a early 1967-318 casting? Quite a strange combination.
The casting batch is a 2!!
Wow!!
Thanks everybody for the input. I have talked to four different people that say they have 1966 motors but have the 2465315 casting number heads. I just don't understand it. Every thing I read says they are not compatible.
In reality, the only difference is probably the size and angle of the intake mounting bolts. They were closed chambers until 1968 ish.
68 CUDA FORMULA S
Well-Known Member
I have been watching this thread to see what you guys came up with so I went out to the garage to look at my 66 273 motor and see what kind of numbers mine had on it. My block casting numbers are 2465330-3 my pad numbers just under the drivers side head are B-273 9-10 and I pulled off the drivers side valve cover for the head casting numbers and it reads 2465315-3 I did not pull off the passengers side cover. Also on that drivers side head next to the casting numbers are some other numbers, they read 06025 can any one shed some light on what these numbers mean. If someone can tell me what all the numbers mean that would be great. This is a 66 273 2 bbl motor not a commando motor.
Thanks
Bob
Thanks
Bob
Is that the motor you got from me Bob? That would be the original motor from my 66 Cuda if it is! My car has a build date of 2-3-66!
As for the other castin numbers in the heads?? Someone wiser than me will surely know!! Geof
68 CUDA FORMULA S
Well-Known Member
yep this is the motor that I got from you Geof, one of these days I will go through it and it will go back into a 66 barracuda. So going by what you posted the B is for 66 273 motor and then 9-10 is September 10th thats what the block pad reads?
Until a casting is machined, no one knows where it's going. The fact that 315 casting have turned up in 66 engines, even though they are supposed to be 64-65 heads, just means there were alot of raw castings waiting to be machined; if you will, it's a documented factory mistake. It feeds into the saying of "don't buy a car built on a Friday, or a Monday".
Yep, that's how it reads out!! Apparently, 273 motors were not selling very well, and maybe a lot of extra parts were hanging around waiting to be used! If this motor i have is any indication, they were just throwing them together at the end of 66!!
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