this may be stupid but......
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From: Duncan, OK, 73533
this may be stupid but......
Can an 89 just be a z-28??? or was the Z-28 an IROC?? Was the IROC a package added to a Z-28 to make it an IROC-Z, if so, what did the package include?
Joined: Jul 2000
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From: In a mint Third Gen!
Car: Red 87 IROC-Z28 T-Top
Engine: 5.7 Tuned Port Injection
Transmission: 700R4 Auto
Axle/Gears: BW 9-Bolt 3.27
85-87: Z28 and IROC-Z28 (option).
88-90: IROC-Z28 only.
It is a Z28 yes, an upgraded Z28.
88-90: IROC-Z28 only.
It is a Z28 yes, an upgraded Z28.
Last edited by IROCZTWENTYGR8; Feb 17, 2002 at 01:06 AM.
Joined: Jul 1999
Posts: 2,926
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From: Tucson, Arizona USA
Car: 1987 Z28 Convertible
Engine: 305 TPI
Transmission: 5-speed
The IROC-Z (RPO B4Z) was an option on the Z28 in 1985 thru 1987. It is a graphics and suspension/handling option. It consists of body-colored lower rockers, specific striping and door decals.
The factory fog lamps originated on the 1985 IROC-Z but was made available on all Camaro variants beginning in 1986. For 1987, it was not available on the RS or Sport Coupe (with the exception being the Sport Coupe with the LT option). The suspension included specifically valved front struts, Delco-Bilstein rear shocks, and a frame stabilizer called the "wonderbar". It also included 16-inch wheels and tires, which necessitated a steering gear box with closer "stops" to prevent the larger tires from rubbing in the fenderwells. The rear springs and sway bar diameters between the Z28 and Z28 with IROC-Z option are identical, although the IROC-Z's stance is 15mm lower. Whether it be a Z28 or a Z28 with the IROC-Z option, "Z28" was used for all exterior badging.
For 1988, the Z28 was discontinued. The IROC-Z became the "base" sport model. Exterior badging changed to read "IROC-Z. GM was so cheap that the interior dash badging was not retooled. So these cars' interior badging reads "Z28/IROC-Z" just as in previous years. In 1988, the 15-inch Z28 wheels (previously used on 1982 to 1987 Z28's) became the standard IROC-Z wheel. The 16-incher was an option. This was true for 1989 also except the '89 15-inch wheel is identical in style to the 16-inch wheel.
The RPO code used for the IROC-Z in previous years, B4Z was no longer used. Instead, RPO Z28 was used for all 1988 - 1990 IROC-Z's.
The factory fog lamps originated on the 1985 IROC-Z but was made available on all Camaro variants beginning in 1986. For 1987, it was not available on the RS or Sport Coupe (with the exception being the Sport Coupe with the LT option). The suspension included specifically valved front struts, Delco-Bilstein rear shocks, and a frame stabilizer called the "wonderbar". It also included 16-inch wheels and tires, which necessitated a steering gear box with closer "stops" to prevent the larger tires from rubbing in the fenderwells. The rear springs and sway bar diameters between the Z28 and Z28 with IROC-Z option are identical, although the IROC-Z's stance is 15mm lower. Whether it be a Z28 or a Z28 with the IROC-Z option, "Z28" was used for all exterior badging.
For 1988, the Z28 was discontinued. The IROC-Z became the "base" sport model. Exterior badging changed to read "IROC-Z. GM was so cheap that the interior dash badging was not retooled. So these cars' interior badging reads "Z28/IROC-Z" just as in previous years. In 1988, the 15-inch Z28 wheels (previously used on 1982 to 1987 Z28's) became the standard IROC-Z wheel. The 16-incher was an option. This was true for 1989 also except the '89 15-inch wheel is identical in style to the 16-inch wheel.
The RPO code used for the IROC-Z in previous years, B4Z was no longer used. Instead, RPO Z28 was used for all 1988 - 1990 IROC-Z's.
Last edited by Willie; Feb 17, 2002 at 08:09 AM.
Joined: Jul 2000
Posts: 7,386
Likes: 1
From: In a mint Third Gen!
Car: Red 87 IROC-Z28 T-Top
Engine: 5.7 Tuned Port Injection
Transmission: 700R4 Auto
Axle/Gears: BW 9-Bolt 3.27
Originally posted by Willie
Whether it be a Z28 or a Z28 with the IROC-Z option, "Z28" was used for all exterior badging. (85-87)
For 1988, the Z28 was discontinued. The IROC-Z became the "base" sport model. Exterior badging changed to read "IROC-Z. GM was so cheap that the interior dash badging was not retooled. So these cars' interior badging reads "Z28/IROC-Z"
Whether it be a Z28 or a Z28 with the IROC-Z option, "Z28" was used for all exterior badging. (85-87)
For 1988, the Z28 was discontinued. The IROC-Z became the "base" sport model. Exterior badging changed to read "IROC-Z. GM was so cheap that the interior dash badging was not retooled. So these cars' interior badging reads "Z28/IROC-Z"
They had to do a few things to remind u that it is still a Z28 by doing that and using Z28 for the RPO. We know it means IROC-Z28, but I've been asked more than a few times what the Z stands for in IROC-Z. (been asked what IROC means enough too 
) Its better that they kept it on there. Last edited by IROCZTWENTYGR8; Feb 17, 2002 at 03:21 PM.
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