Tangovino

Can I determine the build date on the VIN number off my '70 Olds 442.

Fairly lame question; as it's my daily driver.

PS: I got the brakes fixed, thanks to all the input from you guys.

BTW: Thanks Joe!


Mitch

joe_padavano

Mitch,

Thanks for the feedback. It's nice to know when a suggestion works.

There is no way to get the build date from the VIN, however you CAN get the build week from the body data plate on the cowl. There will be a three character code on the left side of the plate, usually in the second line. It will be two digits and a letter. The two digits are the build month and the letter is the week. For example, 12B would be the second week of Dec, 1969 for a 1970 model year car. 04C would be the third week of April, 1970.

mugzilla

I was reading that the iron formula change mid year on the 70s ...

So I was going to ask this question anyways ...

C O .com >***

joe_padavano

Rohebo

Tangovino,

For (old) Corvettes and Chevelles I recall books containing the VIN ranges by build month. So based on the VIN you could determine what month the car was built - and based on the range in the month # even approximate the car's build date.

I'd like to share a story where this information came in handy. About 10 years ago I tagged along with a friend who was inspecting for possible purchase a '70 Chevelle SS LS-6. The owner had this car since 1980 (complete with 1980 inspection sticker on windshield), and was very complete and original.

The engine block stamp matched the VIN, and the engine code stamp was that of an LS-6. But Chevy also includes a date stamp on the pad - in MMDD format (0305 = March 5, with no year listed). The problem was that the body tag showed a December '69 build date. No way the engine was built 3 months after the body, right? Well in this case the list of VINs and build dates came in handy. The VIN was a March '70 VIN, which then makes sense with the block stamped date.

It's likely that something either happened to this body and it was pulled off the line (or something), or perhaps there was some lag with LS-6 blocks and they all had this issue. I've never "touched" another LS-6 so I can't say. But either way the VIN build month list "saved the day".

Just FYI I can't remember the exact dates from the story above, so they're approximate - the dates have been changed to protect the innocent ;-)

mugzilla

Classic Olds is greater than the rest ...

mugzilla

My tag has 11C on it ...

Mid year ...

I'm going to have to go back to FAQ ...

mugzilla

Turns out 70 was a very good year but I have to check the back of the block to see ...

from http://www.442.com/oldsfaq/ofblk.htm#Blocks

Yes the nickel content is what makes the early Old's blocks, and Olds blocks in general, so strong. This is readily apparent if you use a rotary file on the block or heads. Low nickel engines (cheby is prime example) are very easy to take metal off while high nickel engines (like Olds) will take twice as long to remove the same amount of material. Prime example is when you machine the main caps for the strap and stud kit mine came out looking like a mirror (you could literally see your reflection!). At the rear of the block behind flexplate, in the right upper area (cast on the rear face, under the flexplate area,) for an "F" code such as F0, F1, F2, F3, F4, ect. If the block is an early one, the F code will be fairly low.
This numbering and selection of lower is better generally applies to 455 block only. This is open to speculation, because this is the most I've heard on the subject. And yes, conventional wisdom holds that the lower the F-number, the better the block quality for hi-po use - for 455s, which were cast in the late 60s-early 70s period when reduce performance and fuel economy concerns resulted in lower nickel content and thinner walls later in the production run. I doubt this applies to 425s, for example, which were obviously all cast in the early to mid 60s, and would have high nickle content.
The F5/F6 on a 67 425 block is consistent with them being 67 blocks (1967 was the last year of 425 production - presumably 65 425 blocks would be F1 and F2 blocks, for example). The reason why this is not significant on the 425s is that apparently all year 425 blocks are the same with reguard to wall thickness and nickel content, so the "look for a lower F-number" was never an issue. The 455s, however, do vary in desireability with production year, so that's why you've only heard about the F-number in relation to those blocks.
For those seeking to build a really heavy-duty engine, rumor has it that the blocks with a "F", "F1", etc, up to, "F5" or "F6", are higher in nickel, and stronger. Rumor has it those blocks up to the "F2" are the most desireable. These are commonly 1967 to 1970 or so 425 or 455 blocks.
This is not the "F" block ID code found on the timing shelf area. The "F" designation we are talking about here is a large (~1.5" tall) letter cast into the back face of the block, under the flywheel. You obviously need to have the motor out and the flywheel off to see this. This will either be just the letter "F" or "F" and a number up to 6. The 1968's should have the "F" with no number; later blocks have higher numbers. Conventional wisdom holds that the earlier blocks (up to "F2") are higher in nickel content and thus more desireable for performance applications.

Year Model CID Nickel Content Code
'66 330 F4
'67 Non Toro 425 F5
'67 Non Toro 425 F6
'68 455 F4
'68 442 400 F2
'68 455 F2
'68 -'70 350 F4
'69 98 455 F1
'69 Hi-comp 455 F4

'70 88 455 F1

'73 455 F3
'73 455 F4
'76 88 350 F7

350 Diesel F6

joe_padavano

The "F" numbers refer to minor casting core changes, not any metallurgy. It makes no sense that a 1967 425 would be any less "good" than a 1968 455. This is an urban myth about on par with the offset engine myth.

wmachine

X2

First of all, please refer to the Olds wiki now. The old Olds FAQs are "dead".
http://www.oldsmobilewiki.com/index.php/Main_Page
The Oldsmobile Wiki is "alive and breathing". It continues to go through modifications and improvements. I don't think the "block nickel" section has been corrected yet, but I'll get to it. I plan to redo it after I do more material testing of various blocks as actual proof.

Metallurgy 101: Nickel is *not* what will make a block stronger. Nickel is relatively soft, in fact. It would be (and is) added to iron and steel for corrosion and heat resistance. A *much* more logical choice for higher strength would be chromium. So if indeed they are stronger, it is not because of nickel.

Foundry 101: Like Joe says, the F#s are almost certainly revisions the pattern equipment that are a physical change to the casting. Joe- that could be to the block pattern too, not just the coreboxes. But never a measure of an alloy in the castings material.

mugzilla

I can believe the myth since my 455 has 100,000 on it and it doesn't use oil and has excellent compression . I like how the chebby is potrayed as inferior, which we all know to be true ...

I know that after rebuilding a 78 chebby 350 head twice (it failed and was replaced) that 77 and later 350 heads have less metal in them ...

joe_padavano

Funny, since the 454 in my 99 crewcab dually has 210,000 on it currently and has never been apart.

mugzilla

I'm sure they had to fix the problem ...


I saw a 95 fat block at pic a part in a 3/4 ton compleat for $400 . I didn't need one but I still almost bought it. F'r looked new too ...