chevy-man77

just wandering if anyone knew an easy way to tell if your car is accully an iroc/z28 im looking to buy a 89 convertable just want to make sure it is what he says it is not just stickers on the car

tpi-hearse

iTrader: (27)

dash emblem,steering wheel,rims,taillights,hood,145 gauges..etc check for factory iroc options vin# and if it is a tbi Iroc I guess it realy doen't matter

Apeiron

The only way to know for certain is to find the B4Z RPO.

Midwest Muscle

I don't think you will find B4Z on the later model years where there wasn't a distinction between the regular "Z28" and the "IROC-Z". On the later cars (not sure which exact years), they will show Z28 as the RPO. Contrast that to my '85 which does show B4Z as a separate RPO.

Mike M

MNformula350

iTrader: (2)

from 88-90 they were all Iroc-Z's, no Z28's

cdartz

Incorrect. Not for 1989.


For 1985 to 1987: The regular Z28 was designated by, you guessed it, the Z28 RPO code. The IROC-Z was designated by B4Z.


Again this is incorrect, as IROC-Z is simply short for IROC-Z28. The option code for these years is Z28. Basically in these years all were both, unlike in 1985 to 1987 where you could have a Z28 that is not an IROC-Z.


The bottom line is all IROC-Zs are Z28s, but not all Z28s are IROC-Zs. In essence the IROC-Z is simply a higher optioned Z28.

3rdgenstm

There was not a Z28 from 88-90, the IROC was a standalone model. Prior to 88 MY the IROC was an option for the Z28. Chevy dropped the Z28 for the 88-90 MY, but the RPO was Z28 for an IROC car.

In your case, you should have Z28 on the RPO sticker.

cdartz

That makes no sense. How can you say that an 88-90 IROC-Z is not a Z28 when the RPO code is Z28. Hell my 90 IROC-Z says Z28 in huge letters on the dash. Would you like a picture of the badge? As I said above all IROC-Zs are higher optioned Z28s. How can you not see that? Just because GM eliminated the lower Z28 doesn't mean the IROC-Z was now not a Z28 even if it is it's own model.

Casey Butt

Why?

tpi-hearse

iTrader: (27)

why what??????/...I am telling him to check for Iroc options???????? and if it is a Tbi Iroc it is just an rs with badges

92RS(real slow)

Not true they made TBI Irocs I never thought they did, but there out there, they also had some with 15 inch wheels

scottmoyer

cdartz is correct in all aspects. In 85-87, the IROC-Z was a sub model of the Z28. You could order either car. The IROC-Z was an option package. In 1988-90, GM dropped the IROC-Z option package. The performance model for the Camaro was still the Z28. Only now, all Z28s came with the IROC-Z option package as standard. So in essence, as cdartz stated, all IROC-Zs were Z28s or Z28s with the B4Z option package.

GM was reducing the model count starting in 88. The Z28 and the IROC-Z were merged into a single model eliminating the need to have 2 models. All the other Camaro models were merged into the Sport Coupe. You could get a base SC or you could get one optioned almost as well as a Z28. With only 2 models to choose from, it made life easier for GM and parts certification.

Casey Butt

That's why. All IROCs (including TBIs) had stiffer spring rates, larger diameter swaybars, and wonderbar that the RS never had ...even the F41 suspension upgrade for the RS was a softer suspension than the FE2 package on IROCs ...so there were more differences than just the engine and badges.

cdartz

Thanks Scott. I'm not one to gloat, but...

Mcdamit

umm, Z28 rpo in the center console.. a 9 bolt rear end is a dead giveaway if it has a tpi.. VIN would be the easiest

scottmoyer

The VIN does not dictate if the car is an IROC-Z. The only time the VIN would tell you is based on the engine designation of "8". The IROC-Z and 91/92 Z28 were the only cars available with the the 350. Other than that, the VIN does not tell what you have. In this case, the car in question is a convertible, so no "8" in the VIN.

chevy-man77

well i picked it up today it was told it had a 305 tbi in it stock now it has a 355 carb.It has 15in iroc wheels,fog lights,it does have the iroc dash emblem ? either way i got it cheap even if its an rs.I have seen irocs with the 15in wheels, and i seen z28 with the 110/115speedo witch this does have,about the biggest thing i noticed that threw me was the 10 bolt drum rear i thought by 89 irocs all had nine bolts i looked in the console theres no codes in there stickers gone PS just to ask i do need a center spoiler piece if anyone has an extra lying around ha ha good luck right thanks for all the info

Drew

iTrader: (58)

Regardless of any parts that are physically on the car, you won't know for sure unless you have the SPID. Anyone can remove parts from one car and put them on another. Fbodies are very popular cars to the modification happy crowd, and to think that a rear end or badging, or wheels wouldn't be changed in 15 years is ignorance. Get the documentation when you buy, or dont pay a premium for a car that's supposed to be an Iroc.

Kevin91Z

iTrader: (1)

Only the 350 TPI and the 305 TPI with the G92 code got the 9-bolt, in '87 to '89 IROC's. The other engines and lo-po 305 TPI's got a 10-bolt.

labrat

Not entirely true. In 87 and 88 G92 was available on 305 TPI with automatic which included the 3.23 Ten bolt rear end. I have one.

Iroctopless

After reading this topic, I must say Cdartz knows his stuff.

For examples of what's been talked about and for another '89 Iroc vert to compare to, here's mine . . .

My RPO list printed from a GM dealership after running my VIN through there system . . .


No longer a B4Z rpo, but does have the Z28 rpo.

Here is a pic of the Z28/IROCZ dash plaque . . .


And as Scottmoyer mentioned, there's no 8 in my VIN (see top of RPO list above). Sadley no verts came stock with a 350. At least they didn't twist themselves apart to bad then. So as mentioned the VIN really tells you nothing to help determine if a vert is an Iroc.

The LO3 (305 TBI) and the LB9 (305 TPI) were both available on the IROC vert.
IROC's had black painted headlight buckets (as long as it's nobody's changed it).
I believe all '89 verts came with 115mph speedo's regardless of engine or model, so you can't really go by the gauge.

Please correct me if I'm wrong on anything. I was scratching what few braincells I have left, on this post.

A lot of the other things could have been changed over the years, making it quite hard to determine an IROC if a previous owner(s) wanted it to.

roachjuice

my 85 iroc has an 85mph speed o.......

Krazzycowgirl

My 87 Iroc RPO codes has Z28 & B2L which is the IROC package for 87 lol

Drew

iTrader: (58)

Actually, B2L has nothing to do with the Iroc package. B2L is defined by GM as... 'Engine Package - V8 5.7L, PFI'. L98 is defined as 'Engine, 5.7L V8'. The two are related, but not identical codes. Much the same as MD8 and MX0 which both relate to the 4spd automatic transmission. MD8 literally is referring to the 700R4/4L60, while MX0 is the automatic transmission merchandising option. Basically B2L specifies various parts related to the engine, nothing more. B2L isn't an Iroc specific code.

Krazzycowgirl

Yes it is since the engine was a 350 & in 87 the only car you could get the 350 in for the CAMARO was the Iroc

MARO-MAN

I got a '87 305 TPI with the ten bolt posi 3.23!(option codes: G80, G92, J65)
My friend has a '88 convertible with 15 X 8 inch rims. (16 inch rims in '88 on were now an option and not standard like they were in 85-87)
All Iroc-z after '87 have the iroc-z emblems on the ground effects instead of the Z-28 ones, but still have the Z-28 on the dash.

Don't know if you guys have seen this site before, lots of good info:

IROC-Z.com

-Nick.

Drew

iTrader: (58)

That's all fine and good, except B2L doesn't specifically have anything to do with the Iroc package, while B4Z does. Your statement that B2L is the Iroc package is factually WRONG. No point in trying to argue the issue, since the definitions are clear. ALL 1985-87 Irocz's carry the RPO code B4Z indicating the Irocz package. Not all 87 Irocz's carry RPO B2L, because it's not related in anyway to the Irocz package. Having the RPO B2L on an 87 Iroc would indicate that the car is an Iroc, but only because the Irocz was the only platform the L98 was offered under. But then if you've got the RPO's to see that it has B2L you can easily read a few RPO's over to see B4Z.

I hate to nitpick, but honestly, you're posting incorrect information that will only serve to confuse people looking for a fast way to verify if their car is an Irocz. If they go looking for B2L on a Camaro with B4Z and a 305, it's not going to be there, while the car will indeed be an Iroc since it carries the B4Z code.

scottmoyer

Thanks Drew. You saved me some typing. Now this link above appears to be alive again! It's been down for quite some time. Maybe Jeff has taken the time to get update it's information. There is a lot of bad information on that site also.

Abubaca

iTrader: (3)

We just had a similar discussion on another thread regarding RPOs. Sure enough, someone post up with a description of what an Iroc really is and in what years, blah blah blah.

The bottome line is the ONE RPO CODE. Z28/B4Z for 85-87, and Z28 for 88-90.

Forget motor, suspension, rear, gear, color, badge, wheel size, carpet color, and the price of spaghetti. It either has ONE all encompassing RPO or it doesn't.

My brain hurts when so many people say the same thing over and over and then somehow find a way to argue over it.