RPO Code List--Sticky please? 2020-09-30

I started this thread to list common RPO codes from the Service Parts Identification Label that everyone always asks about, like axle ratios, engines, etc. I do not have all of them right now, just the ones that are in my Oldsmobile FSM from 1985. If you think I have left something out, post it here for the benefit of all. I am asking for this to be a sticky because it would be very helpful to everyone.

Engines:

LD5-Buick 3.8 ( 231) V6
LF9-Olds 5.7 diesel V8
LG4-Chevy 305 V8 with 150hp
L69-Chevy 305 HO V8 with 180hp ( 190 in Camaro)
LG8-Olds 307 HO engine in 442
LV2-Olds 307 standard V8

Rear Axle:

GH2-2.29 ratio
GM8-2.56 ratio
GT4-3.73 ratio
GU1-2.41 ratio
GU2-2.73 ratio
GU4-3.08 ratio
GU5-3.23 ratio
G72-2.14 ratio

G80-limited slip differential

G87-8.5in 10 bolt axle
G89-7.5in 10 bolt axle

Transmission:

MV9-3 speed auto ( THM-200)
MW9-4 speed auto overdrive (THM 200 4R)
MX0-Transmission Auto/Overdrive
MX1-Transmission Automatic

Suspension:

V2E-Standard Suspension Designator
FE2-Firm Ride And Handling Package when ordered with Y78 Calais/Salon
F41-Firm Ride and Handling Package

Miscellaneous:

NOS-Stripe Delete
N83-Chrome 15x7 Rally wheels
W42-Cutlass 442 package
Y78-Cutlass Calais ( Salon too?) option package
CF5-Astroroof ( sunroof)
C41-A/C delete
AR9-Sport Bucket seats
A51-Bucket Seats
BS1-Extra Sound Deadener
BX2-Lower Body Side Moldings
CO4-Landau top
UL5-Radio Delete
U21-Gage Package
VO3-Cooling System-Extra Capacity
V08-Cooling System-High Capacity ( Don't ask me the difference either!)
YT1-Deluxe Door Panel Trim
B18- Cutlass Brougham ( Not Sure, but it seems to follow from another description)
ZR6-Show Car
Z49-Mandatory Canadian Base Equipment model

There are plenty of things I left out. If you want to know any of them, post it and I will try to look it up. There are other things that are technically great, like the speedo gear codes, but there were just too many of them to list.

Ok, I found my more complete listing of RPO Codes from a GM book called: GM Production Options, Effective May, 1984. I will add some more info from that book here. It is about 20+ pages long, with over 100 entries per page, so if you need to know something it probably has it.

Engines:

LC3- Chevy 229 V6 ( 3.8 liter)
LC4-4.1 V6 ( Buick?)
LC5,LC6,LC8,LD5,LM9,LN3-231 V6 Buick
LG3,LE9,LF3,LG9-305 Chevy V8
LT8-4.1 V8
LV8-260 V8 ( Olds)
L26-200 V6
L27,L37-301 V8 (Pontiac)
L39-267 V8 (Chevy)

Aluminum Bumper Codes:

VD6-Aluminum Front Bumper Support
VD7-Aluminum Rear Bumper Support


There is a wealth of stuff here like the rear axle codes that are stamped on the housing. I will work on adding them at a later time.