I have a 5 363, and it was sold to me as a 66 442 400 E block. So would 5=1965? Cause its not a 1 2 or 3 that's for sure...

 

Not likely.
Are you SURE it's the E-400 block?
I wrote in the above that "allegedly" the markings are
Calendar Year
Julian day of that year

But, if you have an E-400 with a "5" then that's pretty proofy that the upper digit is not in fact the calendar year. I would love to see and store that photo set. Also, I believe I have a photo of a 350 or 403 with a "17-xxx" emboss here, and no Olds engine type ever ran for 17 calendar years.

In my limited experience, it -usually- works out that for example a 1968 model year block will bear a 1-xxx or 2-xxx block "date" emboss.

So, to sum it up, based on the "not really dependable" first digit in the block's date embossment, all we can state with reasonable certainty is that the second part, the Julian date, is that many days into "some" calendar year. And, therefore, to anser the original question...


No, there is no way to tell FOR SURE whether it was originally a '66 or '67 model year engine.

Luckily, it does not matter, either, for the two are entirely identical, right?

 

My ten 390925 E blocks are 3, 4, 5, 6. Several are almost certainly 1966 and those are 3 or 4.

 

As we've seen previously, the large digit is the mold number and is only loosely related to the casting year. Documented 455 blocks similarly vary in correlating the mold number to the model or casting year. On the 68-up motors, use the VIN derivative to ID the model year. I realize that's not possible on an E-block.

 

Yes its definitely an "E" block. I'm pretty sure I have a 67 E Block with a Julian 003? something like that.... I'll try to drag it out and have a look at that number. May be a week or two before I can get to it.

 

Therefore, for E blocks, that distributor area embossing first character is not loosely, not even REMOTELY related to the calendar year of casting. That's good data to have right there. Shoots down the "first character = calendar year" theory. Which leaves us back to

4
123

means "Mold #4" or version #4 of that mold...
Day 123 of some undetermined year. No way to tell, prior to 1968 model years.

I have noticed a large stamp on the block right where the starter goes, typically 4 digits, it would be cool if that was a Julian YDDD format or similar. Probably a sequential engine line processing number.

 

Note: These are not pics of the item for sale!!!!


Note: These are not pics of the item for sale!!!!

BTW on the 442bro.com website he has two B blocks, both with 2's and the Julian date codes 93 and 121. So if I had just the info from this post I would tend to think that 65 400's were 2, 66 3 and 4, 67 5 and 6 ????

 

There you go, if the series starts with any 400 after the 394.... Then the '65 400 started in CY '64

1-64
2-65
3-66
4-67

huh, no "5"

back to "mystified"

Now I gotta go look at the junk E-400 in the garage.

 

Service replacement blocks?

 

According to Run to Rund's post the definite 66 blocks he has are 3 and 4, so maybe it's
1-64
2-65
3,4 66
5,6 67

 

FWIW, I have five "E" blocks, four '67 and one '66,
all, but one, of which I personally removed from the cars they were in.
(The one is still in the car.)
That's not to say these were necessarily original engines in those cars,
although I'm confident that all but one were original to the car they were in.
The one I know is not, but I'm sure it's a '67 engine.
The '66 engine is a "3".
Two of the '67 engines are "4".
The other two '67's are "5".
The "4" is the one that I know is not original to the car it's in,
but a good friend, who I got the car from, bought it from a junk yard
back in the late '70's and saw it removed from a '67 car first hand.
I'm guessing the "4" engine could be late '66 and/or early '67.
My 2 cents worth.

 

So THATS why E block engines are hard to find. Members here have them all

 

Except for the '66 engine, I've had the rest for 25 years plus.
The '66 for over 16 years.
Couldn't afford to buy one today.

 

From Bro's website more info on the casting numbers.

 

Excellent info, thanks.

 

I really think everyone is reading waaaaay too much into these mold numbers. They APPROXIMATELY correspond to casting year, but not exactly. Unless someone has an Oldsmobile engineering document that specifies the use of the mold number by year, we're only guessing. It's like the "F" numbers allegedly corresponding to nickel content. People only claim it applies to 455s, but every 64-90 Olds block has them.

 

I basically agree Joe but the evidence is mounting that 1=64, 2=65 , 3-4=66 and 5-6=67. Please try as best you can to dispute this with known blocks and history because I don't want to be correct, I want to be accurate.

 

And what about 330 motors? 425 motors? Does "1" indicate 63 for the 330s? This is why I remain unconvinced. Everyone focuses on a single displacement and not the global engine production issue. Why would the numbers for year differ by displacement? Makes no sense (though Chris will correctly point out that GM's date coding makes no sense anyway...). It makes far more sense that the numbers refer to molds, which ARE displacement-unique. The molds MAY roughly correspond to year of casting, but not exactly.

 

Many car enthusiasts that have no connection to either car manufacturing or production engineering in general assume things were and are waaay more orderly than they actually are.

 

Joe, referring to your comment about displacement, the first pic above is a 330 a "supposed 1964 block". Since they made 330's for several years it
s harder to determine what the (Mold) numbers may mean; but, if we look at the "B" block (one year only) that may answer some of the questions.

If someone can show a B block with a 1 or a 3, (or other), then the "year theory" falls apart immediately.

A 1 or 3 would certainly indicate that the numbers are "Mold" numbers , but if all B Blocks (meaning every car or block that is checked ) turn out to be 2's and there probably were dozens of molds making B Blocks , then what does a mold number actually indicate?

There were 25,003 442 options sold in 1965. If all of the currently known blocks have a #2 on them, then saying it's a "Mold" number has no real meaning. What that's really saying is "I have no idea what the heck that number is"

I just asked someone to look at two of their "B" blocks, so stay tuned.

 

My point is, why would a "2" on an early 400 block refer to a different year than a "2" on a 455 block?

 

Joe, my only guess (and it's a SWAG) is that the 455 was introduced in 68 and a 1 would be for year 68 ??? I haven't looked into the 455's at all except when early on everyone was saying all the stuff about the high nickle content and F numbers.

 

My point is, why would you use "1" to mean 1963 on 330 motors, then use "1" to mean 1964 on 400 and 425 motors and THEN use "1" to mean 1967 on 455 (and presumably G-block 400) motors? And did Olds also restart with "1" on the E-block 400 or continue from the B-block? If they continued, why didn't they also continue with the G-block?

Sorry, but the correlation of this digit to year just falls apart as far as I'm concerned.

 

DUH! are these blocks , 330s, 400s, 425s? I think this theory may even disprove itself? Says the 1 is 64 and 340th day? If it is indeed the 340th day of 64, then the engine would be for a 65 model - eH?
Im with Joe P with skepticism of this theory. I DO believe Rund, and I have also had a "few" E- blocks in my time with the various numbers. To lay the theory to rest for me is that i am convinced that ANY E-block is suitable as "correct" for a 66 or a 67 442! (as long as the date code corresponds with the build date on trim tag).
Until there is "clear an convincing" evidence that the actual year of the block can be determined, I will stick to my belief. MOO

 

Over on the W29 site, there's someone who claims to have a B-block 400 with 1 and 51, which under the 1=1964 theory would indicate the block was cast in Feb 1964. This motor came in a 1965 442 with an 03C date code on the Fisher Body Tag. Does anyone really believe the block was cast a whole year before the car was built? Or does it make more sense that the block was cast in Feb 1965 for a March-built car?

Of course, that blows the whole "big number is the year" theory.

Note: I moved this whole part of the thread out of the Parts For Sale forum into it's own thread.

 

 

Do you mean to sit there and tell us it took you THREE years to come up with this info!

 

Given my filing system, I'm lucky it only took that long.

 

Still learning about Olds vs my Chevy background. And while looking up info on date codes I found this old thread and decided to ask my question here. I have a 67 CS 442 and trying to verify all the numbers that I can on it and have a question about date codes on the heads. The engine and manifolds and q-jet and trans and power steering all fit the car. Not that it is numbers matching but at least appear to be numbers correct. I do have cast # 394548 "C" head and on the right one I have V226712G and I see that is correct for the car. but the question is what and where are the date codes? I have 194 embossed on the head and beside the letter "C" there is 11 and as well are the letters CFD which is for foundry info. Any clue will be appreciated. In looking at the posts here, is the 194 the day of the year for casting the heads but which year, the year of '66 or '67? and what is the 11 for? So far everything number wise fits the car. The only other? is where is the part # for the rear end housing located. I was told ti is located on the right side of diff and towards the front of the car but cant seem to find. So if that is correct and it is not there it probably is from another car? So are all housing #'s for Olds located in same place? Also, does the # 226712 from the head stamping correlate to anything. Thanks, Mike