what year did they start to use computer selected springs? My 89 IROC has only FE2 for suspension code.? I thought i had these number codes. I have 5 other codes that i have no idea what they are, IAY,ISD,ISZ,15P,E7Z,AND R6C but i don't think they are for the springs. Any answers to these questions or the names for the codes very helpful. thnx THE SHAGGY IROC

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'89 SHAGGY IROC
L98 7r4, all free stuff,T.E.S.,HOOKER CAT BACK,KYB,ACCEL8.8,JET fan sw. etc.
so much to do , so little money

 

all thirdgens used computer selected springs... how that computer selected the springs is a bit of a mystery. For an 89 Iroc chances are you have 6ZX & 7ZX for the front springs, and 8NL & 9NL for the rears... Thats just going from the data I've collected so far.

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Drew
The lone Thirdgenner of the Apocalypse
predatorman@hotmail.com
My Website
87 Iroc
91 Formula 14.3@98mph
91 RS Convertible
91 Firebird V6
92 S10
98 Grand Am GT

 

1SD is option package 4, does anyone know what is included in this?

irocnroll89...do you have t-tops??
thanks

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90 IROC 5.7l (L98)
ram air, K&N's, air foil,Flows

LIKE A ROC

 

yes i do have t-tops )(cc1). Also i think i have seen those id numbers on a paper tag on the spring when i changed my rearend. Is this where you guys are getting the 9nl...... codes from???

 

they should be on that sticker

 

IAY OR 1AY???
1AY Stock Order Processing Code

ISZ OR 1SZ???
1SZ Discount, Option Package

E7Z Speedometer Adapter (Delete)

15P WHEEL COLOR SILVER METALLIC (91)
This looks kinda odd.. since you have an '89

R6C appears to be some tpye of internal sales control code

 

Actually for whatever reason the tags on the springs themselves will start with a letter rather than a number. The rpo sheet shows two different codes for left and right but in reality the springs are identical. Since they're identical the springs physically will be labled the same with a letter prefix to designate a set rather than left of right... Did that make sense? I don't exactly have it figured out yet, but I'm getting there.

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Drew
The lone Thirdgenner of the Apocalypse
predatorman@hotmail.com
My Website
87 Iroc
91 Formula 14.3@98mph
91 RS Convertible
91 Firebird V6
92 S10
98 Grand Am GT

 

you could probably find some info on the spring load rates and stuff from Mubea if you can't find them from gm.. mubea made them for gm.. well.. they did when i worked there a couple months ago