PO1's/ PO2's

[Tom M.]

Can some one please tell me what is the part number used on PO1/PO2 hubcaps. I am pretty sure both use the same part number. Thanks Tom

[William C.]

Re: PO1's/ PO2's

3923630, at least in service 68-74

[Tom M.]

Re: PO1's/ PO2's

Thanks Bill, I have a query, I have a set of PO2's (flat centred) with part # 3963403 obviously not of a corvette, does any body know what these are off.
Thanks Tom

[Gregory M.]

Re: PO1's/ PO2's

Tom,
A good chance they were off a 1970-73 Camaro...I know a variation of the PO2 was offered on those second gen Camaros and I believe the differnce was the center cap. I dont know it for a fact but it is the only other chevy I have seen those style wheel covers offered on.
GM

[Tom M.]

Re: PO1's/ PO2's

Thanks Greg, was told they were PO1's when I bought them, you live and learn.
Thanks again Tom

[Gregory M.]

Re: PO1's/ PO2's

Tom,
I have seen the reference to PO1 and PO2...what is the difference, if any? I beleive the PO1 was offered on 1968 only, but is there a physical diference?
GM

[Paul B.]

Re: PO1's/ PO2's

...don't know if it was Camaro's that they came on. Thought they were 14 inch wheels, unless it was a Z/28 with these hubcaps. These "flatcaps" were optional on Monte Carlo's which had 15 inch rims in the early '70s. I also have been told there were differences in the '68 cap vs '69 and up, but when that "breakpoint" happened is anyone's guess. I've heard, let's say, the "early" caps had raised ribs that were more flush as they met at the center conical cone(not raised as much). Also, supposedly the chrome circumference "ring" of the center conical cone was narrower on these "earlier" caps.

[Tom M.]

Re: PO1's/ PO2's

From what I have read Po1's have a raised centre and PO2's are flat, but have seen cars advertised with "PO 2's" which were raised, so not 100% sure. PO1's were a one off only on 68's, which is why I wanted a set. Ebay have a couple of sets of what they are calling PO2's which have the raised centres. Have only been able to see them in pictures, apart from the "PO1's" that I bought.
Tom

[Gregory M.]

Re: PO1's/ PO2's

Ahh...good point...14" on Camaro and 1970-73 Z28 all had a 5 spoke painted mag with trim ring an center cap.

I was unaware they were optional on Monte Carlos but it would make sense as they did use 15" rally wheels on Montes...

I am still not sure what the differnce is between PO1 and PO2 wheel covers...

GM

[Joe L.]

Re: PO1's/ PO2's

Tom-----

There never was a finished wheel cover of GM #3963403. As far as I can tell, GM #3963403 was a casting number for the center hub component of the GM #3963405 cover assembly. The hub was once available separately as GM #3963402. This hub (and, the wheel cover assemblies it was part of) were used on some 1970-72 Monte Carlos as well as some late 1969 through 1973 passenger cars. They are similar to the Corvette PO-1/P-02 wheel covers. One difference is the fact that the 3963405 covers have a "flat" center emblem whereas the Corvette have a "convex" emblem.

As Bill mentioned, GM #3923630 was the part number for the Corvette optional cover. It was used from 1968 through 1974. The PRODUCTION and SERVICE part numbers were the same throughout the 1968-74 period. However, the GM #3923630 wheel covers were used in PRODUCTION as a packaged car-set and known, as a SET, as GM #3963629.

Although there, apparently, were minor changes in the wheel covers which occurred sometime in the 1968-69 period, the part number bever changed.

Some folks have theorized that this change resulted in the change of the RPO code from PO-1 to PO-2. Personally, I doubt that was the reason for the change, although I do not know what the reason was. The fact is that RPO designations are more-or-less "generic". Very often, the installed components that make up an RPO do change over time but the RPO designation is not changed. Even within a given model year, the component parts of an RPO change as to part number(s)with no change in the RPO designation.

In this case, there was only ONE part number associated with the RPO and that part number never changed over the 68-74 period. It's hard for me to comprehend that GM would have changed the RPO designation as a result of a minor change to the configuration of the one component of the RPO which didn't even merit a change in the part number of the piece involved.

[Michael B.]

Re: PO1's/ PO2's

Here is a picture of the PO2 wheel cover for 1969. The early 1968 cap was different in that the outside edge came almost straight up to is maximum height where the 1969 cap has the stepped cap. The finned portion was the same.

It is my understanding that the PO1 wheel covers have the flat cap, are plentiful and cheaper to buy. The caps and emblems are available reproduction and interchangeable between all three types. The most cost efficient way to get a set of these PO2s is to find some PO1s with good fins and outer edges and then replace the caps with repos (about $200 a set of 4).

[Tom M.]

Re: PO1's/ PO2's

Hi Mike, it has been my understanding that your car has PO1's and PO2's had the flat centre, correct me if I am wrong, but there seems to be a lot of indifference regarding PO1's Po2's. Thanks Tom

[Michael B.]

Re: PO1's/ PO2's

My tank sticker shows PO2. Here is a page from the 1969 brochure, which shows the stepped center cap.

I did a little more research and find that PO2 were often referred to as deluxe or simulated wire wheel covers. The flat center caps were never used on the Corvette. I thought that the flat caps were on the Monte Carlos but I see the same raised cap in their sales 1971 brochure.

I have seen the PO1 designation used for wheel covers, which look nothing like the finned 1969 covers. I'm not sure the two designations weren't used generically for deluxe wheel covers that are different model and year.

[Michael B.]

Re: PO1's/ PO2's

These are also referred to as PO1 Wheel covers in GM brochures.

[Dick W.]

Re: PO1's/ PO2's

PO 1 and PO 2 were used generically for deluxe wheel covers throughout the Chevrolet. The Corvette PO 1's looked nothing like the last photograph. The difference in the 1's and 2's was very minor and without close inspection you would not notice the difference