Group Option Codes
| Group 1 - No number precedes Group 1 | |
| D ~ Power convertible top [RPO C06] | E ~ Tinted glass (all) [RPO A01] |
| F ~ Power bench seat [RPO A41] (1) | G ~ Power tailgate [RPO A33] |
| O ~ Two-tone paint [RPO 950] | T ~ Power bucket seat [RPO A46] |
| W ~ Tinted windshield (only) [RPO A02] | X ~ Power windows [RPO A31] |
| (1) Reported but no example found to date. | |
| Group 2 - preceded by the number "2" | |
| B ~ H.D. 3-speed floor shift [RPO M13] (1) | E ~ Unknown (4) |
| G ~ Center console [RPO D55] | H ~ Heater delete [RPO C48] |
| K ~ Air conditioning [RPO C60] | L ~ 4-speed transmission [RPO M20] |
| M ~ Powerglide transmission [RPO M35] | Q ~ 4-speed transmission [RPO M21] (2) |
| R ~ Rear speaker [RPO U80] | S ~ Rear antenna [RPO U73] |
| T ~ Rear power antenna [RPO U75] | Z ~ (3) |
| (1) Standard 3-speed transmission on all SS396 but so far only Kansas City has surfaced with this code. Atlanta and Flint are known to use no code when no optional transmission is ordered. Neither Baltimore nor Fremont used group option codes. | |
| (2) Debate whether this does indicate the optional M21 close ratio 4-speed. It has been found on numerous trim tags with known M21 option and the "L" code is not present. | |
| (3) Found on one suspect Atlanta trim tag. Mislabeled in a popular reference book and generated fake tags. | |
| (4) Found on one suspect Atlanta 04D body plate. | |
| Group 3 - preceded by the number "3" | |
| B ~ Rear window defogger [RPO C50] | |
| Group 4 - preceded by the number "4" | |
| F ~ Convenience group [RPO Z19] (1) | U ~ Spare wheel lock [RPO P19] (reported but not verified by any examples) |
| (1) The Factory Assembly Instruction Manual shows both RPO Z01 and RPO Z19 as Comfort & Convenience Groups but neither GM's Accumulative Production Report nor Options and Accessories When Installed By Chevrolet list RPO Z01, only RPO Z19. The Factory Assembly Instruction Manual shows all items under Z01 as being transferred to Z19 so only RPO Z19 is listed. | |
| Group 5 - preceded by the number "5" | |
| B ~ Front/rear bumper guards [RPO V30] (unverified) | Y ~ Deluxe seat belts [RPO A39] |
| Z ~ Shoulder belts [RPO A85] | |
1966 Atlanta only - L code is uncertain at this time but it is not part of Group 5 option codes. The letter "L" appears on the last line of body plates at least up through the 2nd week of March (03B). Sometimes on the last line by itself and sometimes following any group 5 options. Body plates 03C and later after do not have this letter and its meaning is currently unknown.