1965-67 U.S. Corvair Regular Production Option (RPO) Decoding

By Kent Sullivan

Team members: Larry Claypool, Mark Corbin, Stan East, Bill Hubbell, Dave Newell, Dave Trull

This article was published in the May, 2005 CORSA Communique.

Introduction

This article is the second of two regarding Regular Production Options (RPOs) for 1965-67 Corvairs built in the U.S. The first part, which detailed production statistics for these options, was published in the March, 2005 CORSA Communique. This article documents the system of codes that Fisher Body used to represent RPOs on the engine compartment body-tag. Note: 1965 Greenbriers, like all Corvair forward control models, do not have this tag and are therefore not addressed in this article.

Fisher Body divided the tag into several sections indicating paint, trim, production data, body style and  optional equipment. The RPOs were coded on the bottom left section of the tag. Unlike the other areas on the body tag, this area does not have a caption or label.

The lower portion of the body tag has letters stamped in the tag for each option installed on the body. (Options that have no impact on the body, such as hubcap selections, are not coded on the body tag.) The option-code letters are stamped on the tag in five separate groups. The first letters are in Group “1” and this group doesn’t have a “group” label. Groups “2” through “5” follow in sequence and each of these groups is labeled: 2,3,4, and 5.  For example: L2D5ZY indicates: Group 1 = L, Group 2 = D, Group 3 = none, Group 4 = none, Group 5 = Z and Y. If there were no options that impacted the construction of the body, this area of the body tag was left completely blank.

A single letter, printed in one of the five groups, represents each option. The options do not appear in alphabetical order within a group but they always appear in the same order (if present).

The codes on bodies built at Willow Run were printed on one line with no spaces. The codes on bodies built at Van Nuys (Los Angeles) were printed on two lines (groups 4 and 5 on the second line) with spaces between the groups. Table 1 provides an example from each factory.

Table 1: Los Angeles and Willow Run RPO Code Examples

As a side note, there appears to be an inconsistency in representing how one option that required another option was handled. For example, both the deluxe center rear seat belt (AL5) and the deluxe front shoulder belt (A85) required deluxe front and rear seat belts (A39). The examples to date show that, in the case of the deluxe center rear seat belt, only its code appears; while in the case of the deluxe front shoulder belt, both codes appear.

Understanding the Fisher Body Codes

Unlike production statistics, which are fairly readily available for each Chevrolet line, information about how Fisher Body coded options on the “cowl tag” (a term used for this tag in all Chevy lines except Corvair, which does not have a cowl) is sparse. The decoding project done for 1967 Camaros by the Camaro Research Group stands out as a superb example.

As with production statistics, Canadian Corvair owners are in a better situation. There was no Fisher Body in Canada and GM Canada chose to use the standard RPO codes (A02, M20, etc.) on the body tag. Decoding is as simple as looking up the RPO codes in the assembly manual or dealer ordering information. The Canadian system applies to other Chevrolet lines built in Canada too and also pre-production U.S. pilot cars. Note: There are a few RPOs present on Canadian tags that were not coded in the U.S. and vice versa.

Beginning in 1968, Fisher Body stopped using this coding system and, in fact, did not code RPOs in any way on the body tag. From the few build sheets that survive from 1968 and 69 Corvairs, we know that Fisher Body did list the RPO codes (A02, M20, etc.) there. Build sheets prior to 1968 used the same 5-group coding system as the body tags.

Note that the RPOs coded on the Fisher Body tag are only those which required Fisher Body to take an action. These actions ranged from modifying the body to accept a part from Chevrolet during final assembly to actually installing a part. In other words, the body tag options are not at all a complete record of the RPOs installed on a given car. Canadian owners again have an advantage because the complete list of RPOs for a given car is available from GM Canada’s Vintage Vehicle Services for a nominal fee.

Also, as discussed in the first article, remember that some items were also available as dealer-installed accessories, so the lack of a Fisher Body code does not necessarily mean that it was added to the car after it was sold—just that it was added after it left the factory. The dealer-installed accessory brochures for each year provide the list of such items.

Table 2 lists every known Fisher Body code for 1965-67 Corvairs and includes three options for which we expect there to be a code but have not found an actual example. To create the table, we combined data from many sources:

Table 2: 1965-1967 Fisher Body Tag Codes, Grouped by Category

With very few exceptions, the meaning of each code was quite consistent across these three years. The same codes were also used in both plants, again with very few exceptions. These exceptions are discussed below in the "Notes on Table 2" section.

For many of the codes, you might wonder what action Fisher Body had to take. Table 3 provides some examples.

Table 3: Reasons for selected codes

Notes on Table 2    

Group 1

Group 2

Group 3

Group 4

Group 5

Mystery Code

Headrests

Although not encoded with the other options, the Fisher Body tag does indicate whether a Corvair has headrest front seats (RPOs A82 and AS2). The information is indicated by a single-letter suffix following the three-digit trim code. These letters were known as “exceptions” to the trim code, to indicate special equipment related to the upholstery section of assembly. Table 4 summarizes the data.

Table 4: Headrest trim code exceptions

Note: The information in Table 4 for 1966 was first published in the February, 2002 CORSA Communique and can also be found here on my website.

The different letters helped the workers at the Los Angeles plant to remember to install a different type of upholstery in 500s (bench) vs. Monzas and Corsas (buckets). As to why Willow Run didn’t use this system, we can only speculate that it had something to do with the internal plant operations.

We haven’t been able to locate a ’66 500 with headrest seats built in Los Angeles so the code for that combination is unknown at this time. If you own a ’66 500 whose body tag has a trim code suffix of something other than A or E, please contact me!

Although based on limited data collected to date, the trim code exceptions used for 1967 Corvairs appear to be a hybrid of the codes used at Los Angeles and Willow Run in 1966. Remember that Corvairs were built only at Willow Run in 1967. This indicates that cars equipped with RPO AS2 would have trim code suffix E and RPO A82 would have a Y.

Next Steps—Decoding Other Years

When looking at Corvairs produced before 1965, the Fisher Body codes for 1964 are reasonably similar to 1965 and later. 1960-63, however, are often quite different, especially at some of the plants; Oakland being a prime example. In the future, our team hopes to publish more articles documenting and comparing those years.

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Last updated: March 20, 2006.