Lb9 irocz
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Joined: Mar 2025
Posts: 7
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From: Phoenix
Car: 1985 IROC Z
Engine: LB9
Transmission: 700
Axle/Gears: 3:43
Lb9 irocz
Is true that there were only 205 lb9 irocz made in 1985? If that's the case I have one, but it just doesn't seem it would be that few
Last edited by Chopper858; Mar 12, 2025 at 11:21 PM.
Thread Starter
Junior Member
Joined: Mar 2025
Posts: 7
Likes: 0
From: Phoenix
Car: 1985 IROC Z
Engine: LB9
Transmission: 700
Axle/Gears: 3:43
Re: Lb9 irocz
Yes, you are correct. Mine has the 3:42 gear and center counsel clock which i dont see that many. Just got mine recently from the original owner of 40 years last week.
Joined: Oct 2020
Posts: 1,354
Likes: 634
From: Franklin, KY near Beech Bend Raceway, Corvette Plant and Museum.
Car: 1992 Pontiac Firebird
Engine: 5.0L L03 TBI
Transmission: 700R4
Axle/Gears: 2.73
Re: Lb9 irocz
It's a good looking IROC-Z.
Post a picture of the Service Parts Identification label in the center console.
Post a picture of the Service Parts Identification label in the center console.
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Joined: Jan 2023
Posts: 114
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From: Vancouver Island, 🇨🇦
Car: 1989 RU7 1LE / 1997 RS
Engine: 305 TPI / 3800 Series III
Transmission: T5 / T5
Axle/Gears: 3.45 / 3.23
Joined: Oct 2020
Posts: 1,354
Likes: 634
From: Franklin, KY near Beech Bend Raceway, Corvette Plant and Museum.
Car: 1992 Pontiac Firebird
Engine: 5.0L L03 TBI
Transmission: 700R4
Axle/Gears: 2.73
Re: Lb9 irocz
I'm not a Camaro expert by any means but I can assure you that there were more than 205 LB9/700R4 IROC-Zs made with a 3.42 gear ratio. Maybe there were 205 1985 IROC-Zs made with LB9/700R4 and GU6/G92.
@scottmoyer Is the guy that can tell you about it. He is the resident Camaro expert and for sure is on the earlier model 3rd gen Camaros.
To the best of my knowledge only the IROC-Z could get the 3.42 gear ratio with the LB9/700R4. The Z28 couldn't get the 3.42 gear ratio with the LB9/700R4. The best high performance gear ratio the Z28 could get was 3.23.
I think the 3.23 was the standard gear ratio on a LB9/700R4 IROC-Z and the 3.42 was optional with the G92 Performance Axle Ratio. At some point in time the 3.42 gear ratio became standard equipment on a 1985 IROC-Z with the LB9/700R4.
I think you could also get these cars with some other dumbazz optional airplane/highway gear ratios too.
My friend has a 1985 IROC-Z that is G80, GU6, J50, J42 but it's not a G92 car.
@scottmoyer Is the guy that can tell you about it. He is the resident Camaro expert and for sure is on the earlier model 3rd gen Camaros.
To the best of my knowledge only the IROC-Z could get the 3.42 gear ratio with the LB9/700R4. The Z28 couldn't get the 3.42 gear ratio with the LB9/700R4. The best high performance gear ratio the Z28 could get was 3.23.
I think the 3.23 was the standard gear ratio on a LB9/700R4 IROC-Z and the 3.42 was optional with the G92 Performance Axle Ratio. At some point in time the 3.42 gear ratio became standard equipment on a 1985 IROC-Z with the LB9/700R4.
I think you could also get these cars with some other dumbazz optional airplane/highway gear ratios too.
My friend has a 1985 IROC-Z that is G80, GU6, J50, J42 but it's not a G92 car.
Re: Lb9 irocz
I need to research the numbers on an '85, but the Z28 came standard with 3.23s with the LB9. The IROC-Z, being a Z28, also came standard with 3.23s, but when mated to the LG4. The 3.42 gear was an option that came with the LB9, only available on the IROC-Z sub model. So, the actual number produced will equal the number of IROC-Zs with the LB9. Since GM didn't keep track of package combinations, it's hard to say what the actual number is. Especially since the option package combination is Z28/IROC-Z option package/LB9 engine option package.
Thread Starter
Junior Member
Joined: Mar 2025
Posts: 7
Likes: 0
From: Phoenix
Car: 1985 IROC Z
Engine: LB9
Transmission: 700
Axle/Gears: 3:43
Re: Lb9 irocz
It makes total sense. I just got it and my neigbor is offering me 25k for it which is a lot more than what I bought it for, so I start doing some research to see what I actually have. It's my car actually worth 25k? With all three numbers matching they're an original. It was owned by the same lady for the last 40 years
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