87 z28 vs iroc-z28 differences?
 

I have an 87 Camaro. It has a 305 with the quadjet carb. Auto trans. The car was repainted and has z28 trim. So so I always thought it was a z28 yet i cant be sure of the paint and stickers since it wasnt factory. How ever when i put the vin into any carfax report type services it tells me it is an iroc-z28. So i went to the 87 camaro tech data page on this site and found the two to have the exact same drivetrains.

So what is the differences in the two models and how can i tell for sure what mine is.

Re: 87 z28 vs iroc-z28 differences?
 

well first of check for wonderbar, check for 16inch rims, hood louvers, but if thats your car in your avatar looks to be a regular z28, you could also check center console, and see if rpo code sheet is there thats your best bet

Re: 87 z28 vs iroc-z28 differences?
 

:iagree: On the 16" wheels check the driver's door sticker to see if it has this for tire size(that is if it's still there given the repaint). In using the VIN to research a Camaro it's problematic given the Z28 is technically an option on the Sport Coupe and the IROC and option for the Z28 (the Berlinetta had the only unique VIN designator). If there is a SPID in your console make sure it's VIN matches your car's.

Re: 87 z28 vs iroc-z28 differences?
 

It does have the 15x7 wheels. But in 87 there was a z28, iroc-z28, and the iroc. So i know that the iroc has 16' wheels. But what is unique to the iroc-z28 that makes it different from the regular z28 or regular iroc.

mine has
15' wheels
louvers in the hood
ground effects kit
85 mph speedometer that cam on all carb irocs in 87

so it is deffently not an iroc but it is still up in the air wether its the z28 or iroc-z28

Re: 87 z28 vs iroc-z28 differences?
 

In 1987, You first had to order the the Z28 option before you could order the B4Z Iroc option. There isn't just an Iroc, they are Iroc-Zs or Z28s

Re: 87 z28 vs iroc-z28 differences?
 

That was confusing, I think what you are trying to say is you could buy a Z28 or a Z28/IROC-Z.

The IROC included in 1987:
16" Wheels
245-50R16 Tires - Look on the door jamb decal
Wonderbar
some enhanced suspension parts
Fog-lamps - might have been deletable

(did the Z28 (non-IROC) in 1987 get the grid style Tailights???)

John

Re: 87 z28 vs iroc-z28 differences?
 

not to hijack but what are you guys refering to as the wonderbar?

Re: 87 z28 vs iroc-z28 differences?
 

87 irocs got the grid tail lights, i think the Z28 did also.

Re: 87 z28 vs iroc-z28 differences?
 

There was a Z28 and an IROC-Z. There is no such thing as an IROC-Z28. All IROC-Zs are Z28s. The Z in IROC-Z stands for International Race Of Champions - Z28. If your car has 15" rims, then you have a Z28, not an IROC-Z. From 1985 - 1987, to get an IROC-Z, you ordered a Z28 with the B4Z option code. Without the code, you get a Z28, but with the code, you get the IROC-Z. In 1988, that changed. All you needed from 88-90 was the Z28 code because all Z28s were IROC-Zs. GM just reduced the model line to 2 cars, the Sport coupe or IROC-Z.

The rear taillights on the Z28 are also grid style starting in 1985.

The wonderbar is a front end stabilizer that on the front of the car. Do a search and you'll find pictures of one installed and where it connects. It was available ONLY on the IROC-Z.

Re: 87 z28 vs iroc-z28 differences?
 

So have 15' wheels and no iroc rpo code so i cant be an iroc. Yet this chart still confuses me. I highlighted the two models that have my drivetrain. I didn't highlight the LT because i have all the z28 trim and louvers so it cant be that. That leaves the iroc and the "iroc-z28". The plain z28's dont come with carbs and it says they were all tpi. So if there was a such a thing I guess i have an "iroc-28"?


forgot to mention it is also an auto







1987 Chevrolet Camaro Drivetrain List
Yr
Model
Trans
Engine
code/type
CR
Displ.
HP
Torque
Induc-
tion
Manual
std.
Manual
opt.
(G92)
Auto
std.
Auto
opt.
(G92)
87
Sport Coupe
LT
RS*
M5,A4
LB8 V6
8.9:1
2.8 (173)
135@4900
160@3900
MFI
3.42
----
3.42
----
87
LT
A4
LG4 V8
9.3:1
5.0 (305)
165@4400
245@2800
4bbl
----
----
2.73
----
87
IROC-Z
Z28
M5,A4
LG4 V8
9.3:1
5.0 (305)
170@4400
250@2800
4bbl
3.23
----
2.73
----
87
Z28
A4
LB9 V8
9.3:1
5.0 (305)
190@4000
295@3200
TPI
----
----
2.73
----
87
Z28
M5
LB9 V8
9.3:1
5.0 (305)
215@4400
295@3200
TPI
3.08
----
----
----
87
IROC-Z
A4
LB9 V8
9.3:1
5.0 (305)
190@4000
295@3200
TPI
----
----
2.73
3.23
87
IROC-Z
M5,A4
LG4 V8
9.3:1
5.0 (305)
170@4400
250@2800
4bbl
3.23
----
2.73
----
87
IROC-Z
M5
LB9 V8
9.3:1
5.0 (305)
215@4400
295@3200
TPI
3.08
3.45*
----
----
87
IROC-Z
A4
L98 V8
9.3:1
5.7 (350)
225@4400
330@2800
TPI
----
----
3.27*
----
*Borg-Warner rear axle *RS available in only California

Re: 87 z28 vs iroc-z28 differences?
 

Technically no one is an IROC, your car can be tho.

The Z28 base engine was the LG4 (4bbl) Tech section needs some work.

John

Re: 87 z28 vs iroc-z28 differences?
 

Your highlighting didn't come thru. There is no IROC-Z28 model. There is just an IROC-Z or a Z28 as I mentioned before. The tech article doesn't state there is either. Where are you getting this? The tech article refers to 2 models in the LG4 square. The IROC-Z and the Z28. The first box isn't referring to one car as the Sport Coupe LT RS. It's referring to 3 cars and each model is on it's own line. The same with the IROC-Z/Z28 box. There is redundancy in the stats as it has just IROC-Z again further down with the LG4.

You have an LG4 (carbed) Z28. That's it.

edit: I do see that at the very bottom the tech article refers to the quantity of IROC-Z28 as 38,889. That is because the IROC-Z is an IROC-Z28 but it's always referred to as the IROC-Z

Re: 87 z28 vs iroc-z28 differences?
 

----
87
IROC-Z
Z28
M5,A4
LG4 V8
9.3:1
5.0 (305)
170@4400
250@2800
4bbl
3.23
----
2.73
----

That was in post directly from the chart in the 87 camaro data page a few days ago. I do beleive what you say that it is an z28 with no connection to the iroc. Just wanted to point out that it was written on this site. And what someone said before that a z28 base model could come with a carb now makes sense. The chart must not show all the options.

Some one seem to have up dated the chart on that page as now the "Iroc-Z28" was removed and it now just says Z28.

So maybe my curiosity did some good in unintentionally
catching a mistake.

Thanks for all who helped.

Re: 87 z28 vs iroc-z28 differences?
 

You seem to be contradicting yourself there.

Re: 87 z28 vs iroc-z28 differences?
 

No i'm not. There is no 3rd model called an IROC-Z28. Only the Z28 and IROC-Z.

Re: 87 z28 vs iroc-z28 differences?
 

I think it's pretty much assumed that IROC + Z28 = IROC-Z28. If it didn't, then why would they have the Z on the end? It would simply be IROC if the abbreviated Z28 wasn't on the end of it.

Even GM calls it an IROC-Z28

https://www.thirdgen.org/tech/images...left_small.jpg

Re: 87 z28 vs iroc-z28 differences?
 

Cool now i know im not going crazy and that it does exists. Although im pretty sure mine is a base model Z28. Thanks Reid

Re: 87 z28 vs iroc-z28 differences?
 

In 85, GM press called the new TPI mill the 305 HO, while the factory continued making the 305 carb High Output mill.

2 HO motors? No...the right hand did not know what the left one was doing.

The beat goes on.

Re: 87 z28 vs iroc-z28 differences?
 

The lb9 was often called the HO even later on in dealer literature...

On the one hand the car never had the badge of "HO" like the L69, but it was higher output than the LG4 or the LO3 so technically it is not incorrect to call it an HO. So often people are trying to call the LO3 & LG4 the HO engine when trying to sell a car...

John

Re: 87 z28 vs iroc-z28 differences?
 

There are a lot of inconsistancies with the product literature and the actual product. If you read the above page from the 1985 brochure, they are not calling the car an IROC-Z28. They are referring to the car as the International Race Of Champions Z28 or IROC-Z.

This is actually a very petty argument that you're pushing. There is no such car as an IROC-Z28, only the IROC-Z or a Z28. The above article even states that financing your new IROC-Z is as easy as GMAC. They are using the acronyms for International Race of Champions as IROC when referring to the new model of Z28.

GM documentation has been known to be wrong before as they constantly refer to the 350 as the B2L in alot of written material. All Chevrolet engines have an "L" designation for the engine itself. The B2L was a package of required items when ordering the L98. My window sticker even mentions the 350 as B2L, but it's actually an L98.

Re: 87 z28 vs iroc-z28 differences?
 

Yeah man looks like you have a Z28 not an IROC-Z28. The difference that I can tell between Z28's and IROC-Z28's are the suspension and decals. So to make things easier to understand, IROC-Z's are Z28's they just have a beefier suspension and decals.

Re: 87 z28 vs iroc-z28 differences?
 

There is no mistake, the charts are accurate. An IROC-Z's full technical name is IROC-Z28, that's what the Z stands for. There were no Z28, IROC-Z, and IROC-Z28 options to choose from, as the last 2 are the same car. That makes 2 options, not 3. When you ordered it, you had a Z28 with the IROC upgrade, which made it an IROC-Z. You have a base model Z28. Me and SM have IROC-Z's, or IROC-Z28's if you'd like to say it that way. Sometimes literature used the full name and sometimes it didn't, it's really that simple. It's just like how GM doesn't print out Super Sport for it's SS models. If you went into a dealer and said, "I want the new Camaro Super Sport," they'd probably say, "You mean the SS, right?" Then when you said, "No, I want the Super Sport," they'd be like, "OK there.....," LOL! Same situation.

The 85 305 TPI was a more powerful engine than the 305 H.O. with brand new EFI technology, I really think that's all they meant when calling it H.O., but it never got the actual name from GM. That would have been confusing.

Re: 87 z28 vs iroc-z28 differences?
 

1987 IROC-Z28

Re: 87 z28 vs iroc-z28 differences?
 

1989 IROC-Z
http://memimage.cardomain.com/ride_i...105_medium.jpg
The later IROC-Z after the B4Z RPO (to get an IROC-Z Z28) was dropped in '88 and all Z28's were IROC-Z's (88-90) . . .
Just thought I'd throw in my :2cents: to help confuse things! :lmao:

Re: 87 z28 vs iroc-z28 differences?
 

I think the question has been answered to what the poster has. Anything beyond that may go off topic. If we need a new thread, then we can start another.