I posted this one in the 'wheels and tires' forum but there was no reply. Hopefully somebody can help me here..?!



Date codes of my 70 SS wheels:

Near the valve: 8 25 YA

Inside of the wheel: B M1 9(under the M1) H(in a circle) 878 14x7 JJ

This is for all 4 wheels

Who can help?!!!

The numbers that matter here are the ones out by the valve stem. These numbers indicate when the wheel was assembled and its usage.
8=8th month-August
25=25th day
YA=Chevelle SS wheel for 1970

14x7 JJ is wheel size (14x7) and JJ is bead contour where the tire sits. J is the most common contour, and this wheel uses it on both beads.

The other numbers indicate when separate parts of the wheel were built and probably location.

I always thought that YA wheels were for 1969 and AO were for 1970.

The numbers that matter here are the ones out by the valve stem. These numbers indicate when the wheel was assembled and its usage.
8=8th month-August
25=25th day
YA=Chevelle SS wheel for 1970
.
Incorrect, the YA is a 69 SS wheel and the born on date is 8/25/1968
I always thought that YA wheels were for 1969 and AO were for 1970.
You are absolutely correct.

You are correct. YA is the 69 code. I looked in my Chevrolet by the Numbers 70-75, and saw the YA wheel listed, but didn't read all of Colvin's fine print. He says.

"The YA wheel has been documented as being built from November 4, 1968 through July 17, 1969 (1969 model year) Motor Wheel has no record of the YA wheel being used, although wheels do exist. (since this is a 70-75 book, I'm thinking he means for 1970). It is possible that the AO wheel could have been used during the 1969 model year."

I guess I need to read his footnotes better.

So I guess I my case that the YA wheels where also used for the 70 model year..? Like "we've got some left over YA wheels from 69, let's put them on the 70 model"?
Or is it so that the AO wheels where ONLY used for the 70 models..?

Hi Gerard,
If I'm reading your first post currectly where you give all the code info, if the wheels have a date of M 1 to the left of the valve stem and in the center of the wheel, 9 this is the Manufacturer, assembly plant and year of manufacture info.
M= Motor Wheel
1= Romulus MI.
9= 1969
The other info you received is correct, 8 = August and 25 is the day.
I personally have seen and owned 1970 Chevelles and El Caminos with this YA code for the wheel usage on their buildsheets. Every 70 that I have owned with YA coded wheels was a 396 - 375 L78 model which are early production vehicles.
Maybe some L78 owners can chime in here to add some insight to this anomoly, but I am certain about YA wheels having limited usage on 1970 models. Your car wouldn't be an L78 would it?
Anyways , I hope this helps,
Chris
After previewing my post, I can see it may be difficult to interpret the date code because the layout changed when I submitted it.
I intended to put the 9 directly under the M1 codes, but the format changed
with my upload.

Hi Chris! Thanks for your post (and the others also of course) and the layout is clear to me :-). Well I wish I have a L78 car but it isn't. The engine ID is T09CTW so it's a 396 350 (L34). As fas as it isn't a restamp the car is no. matching.
The car trim tag says 10D so it is an early production car (4th week Oct 69).
Hopefully some L78 owners will read this post and give there opinion and can confirm that some 70 models came with YA wheels.

One of the vender catalogs I have lists the YA wheel #3956744 as correct until 10/69, or an Oct 70 car. And the AO #3975651 as correct after 10/69.

It also list a 1st & 2nd designs for the snap in center cap for the YA wheel and a 1st & 2nd design forthe snap in center cap for the AO wheel.

Nothing indicated about which engine.

This would indicate that you should have the YA wheel with the 2nd design center cap.

Don't know how accurate they are; but so far everything about my 66 has been correct.

so where is the LINK that provides the codes?