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Discussion Starter · #1 ·
I purchased a 1973 Mach 1 with a non matching numbers to the power train. I have located the casting number behind the starter. D2AE-CA 4B24. from all the web sites I have understood its a 1972 Cleveland small block, High Output, Cobra Jet, Boss, date code 1974, February, 24th. My question is why does the main number indicate a 1972 yet the date code indicates 1974. Have I misunderstood how to properly decode? If any one could please explain I would appreciate it. Thanks.
 

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1967 Mercury Cougar XR7
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Swirl, this was a hot topic for another engine here recently! There's a simple explanation though.

Ford only changed the casting numbers when they made a significant revision to the molds. So the 'D2' number is definitely '72, when that particular casting was designed. However, they used the same molds and production equipment to make new engines for years! So the date code of '74 being later than '72 starts to make more sense. I'm sure your block was actually made in '74, despite the "D2".

Another great example of this are the E7TE heads. They were first designed to be 'truck' heads, in 1987 (as you'd expect from the E7 part, and the "TE" for "Truck Engine"). But they got use all the way through 1995 (and maybe into 96) when they were superseded by the GT40 (and later GT40P) castings. As a result, if you bought, say, a '94 Mustang, you would see "E7" on the heads instead of "F4".

Best wishes, and welcome to AFM!
 

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Discussion Starter · #3 ·
Thanks for the info, to further the discussion. based on the casting number D2AE-CA 4B24 , can I assume its also a 4 bolt mains?

I have a 351 C with the following confirmed numbers without removing the heads. Right head, has Cleveland foundry logo, with "4D9", clock style casting number of "19753". Left head, has Cleveland foundry casting logo, with "4D8", clock style casting number "1973". Both heads do not have and 2's, 4's or dots in the top left of the heads. So the question, what does this decode to as well would these be Open or Closed camber? I do not want to remove heads so any information would be greatly appreciated. Thanks in advance.
 

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It's probably not a Boss, Swirl, despite the Boss/service block casting number. Even with that casting number, they did not make a Boss in 1974. It's almost certainly just a good 2 bolt main engine. There is always a bit of confusion and excitement over these casting numbers, but there's really nothing particularly special about that number. The fancy casting number means very little in comparison to making sure the engine is balanced and that clearances are correct. Even drilling the block for four bolt mains is not advisable, as the extra holes only serve to weaken the block more. A main stud girdle is more effective, if you want to ensure all-out performance. Your engine should be good to at least 750 horsepower regardless, if properly set up.

If your intake is a 2V, then you can almost certainly count on having the 'open' 2V Cleveland heads too. It's hard to know more without pulling your intake, and taking a peek at the underside of the heads on the intake overhang. There you could find the casting number on your heads - as if the intake ports wouldn't be a dead giveaway too.

While in some ways not as desirable as the 4V closed chamber heads, the open chamber 2V Cleveland heads are still better than any Windsor stock casting, and would make for some great fun!
 

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The block casting D2AE-CA was made to accept two OR four bolt main caps depending on how it was machined at Ford. That casting number was used for '72 and later production. The trouble with internet information is it's not always "clear" on some situations. The same is true for a 289 hipo block versus a regular 289 block. The block casting number is the same but the larger caps were installed to make it into a HiPo. So MANY see the C5AE-E casting and think it's a hipo when it isn't.
Randy
 
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