90 IROC owners: What rear springs came on your car from the factory?
Thread Starter
Supreme Member
iTrader: (10)
Joined: Jul 1999
Posts: 1,780
Likes: 2
From: Fla
Car: 90 IROC
Engine: 406
Transmission: GMPP 93/4L60
Axle/Gears: 9 bolt 3.27
90 IROC owners: What rear springs came on your car from the factory?
I have NNNs on mine, just wondering if anyone else has them on the rear. 
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Black 90 IROC, L98, A4, 323 gear. SuperRamed 406 in the works!
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Black 90 IROC, L98, A4, 323 gear. SuperRamed 406 in the works!
Junior Member
Joined: Jul 1999
Posts: 54
Likes: 0
From: Cromwell, CT 06416
Yes, I have NNN rear springs on my '89 IROC
(LB9 305, G92, N10, N64).
I found a schedule/Job form tucked up in the bottom side of my front driver's seat. I thought I found a treasure map when I pulled it out.
It lists the job #, VIN, Dept., with a number of RPO codes.
It also lists front springs as DB, front struts as MJ. Do you know what spring rates those designate? Or type struts?
- Joe.
(LB9 305, G92, N10, N64).
I found a schedule/Job form tucked up in the bottom side of my front driver's seat. I thought I found a treasure map when I pulled it out.
It lists the job #, VIN, Dept., with a number of RPO codes.
It also lists front springs as DB, front struts as MJ. Do you know what spring rates those designate? Or type struts?
- Joe.
Thread Starter
Supreme Member
iTrader: (10)
Joined: Jul 1999
Posts: 1,780
Likes: 2
From: Fla
Car: 90 IROC
Engine: 406
Transmission: GMPP 93/4L60
Axle/Gears: 9 bolt 3.27
Hey Joe...I guess we are the only ones. 
I dont know about the struts or spring codes you gave. Most of the IROCs ive seen come with BZW front springs, and NNL rears. you can look on the spring it should have a tag on it.
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Black 90 IROC, L98, A4, 323 gear. SuperRamed 406 in the works!
I dont know about the struts or spring codes you gave. Most of the IROCs ive seen come with BZW front springs, and NNL rears. you can look on the spring it should have a tag on it.------------------
Black 90 IROC, L98, A4, 323 gear. SuperRamed 406 in the works!
Joined: Jul 1999
Posts: 10,950
Likes: 26
From: Orange, SoCal
Car: 1990 Pontiac Trans Am
Engine: 355 TPI siamesed runners
Transmission: Tremec T56
Axle/Gears: 12-Bolt 3.73
Mine's not an IROC, but since you mentioned it, I have the NNL springs on mine.
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1991 Camaro Z28
5.7L 5-Speed (originally 305)
13.25 @ 107.18 MPH
Southern California
Member: SoCal 3rd Gen F-Bodies
Webmaster: SoCal F-Bodies
-=ICON Motorsports=-
------------------
1991 Camaro Z28
5.7L 5-Speed (originally 305)
13.25 @ 107.18 MPH
Southern California
Member: SoCal 3rd Gen F-Bodies
Webmaster: SoCal F-Bodies
-=ICON Motorsports=-
Thread Starter
Supreme Member
iTrader: (10)
Joined: Jul 1999
Posts: 1,780
Likes: 2
From: Fla
Car: 90 IROC
Engine: 406
Transmission: GMPP 93/4L60
Axle/Gears: 9 bolt 3.27
MY 91 had the NNLs on the rear too. Kevin.. do you have the CDBs on the front?
------------------
Black 90 IROC, L98, A4, 323 gear. SuperRamed 406 in the works!
------------------
Black 90 IROC, L98, A4, 323 gear. SuperRamed 406 in the works!
Joined: Jul 1999
Posts: 10,950
Likes: 26
From: Orange, SoCal
Car: 1990 Pontiac Trans Am
Engine: 355 TPI siamesed runners
Transmission: Tremec T56
Axle/Gears: 12-Bolt 3.73
Yes I do. Along with the WS6 36mm front sway bar and the 24mm rear sway bar.
Along with the WS6 36mm front sway bar and the 24mm rear sway bar. 
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