i have been talking to several people lately about my car and 9 out of 10 of them think my car is an iroc. my car was wrecked in 1998 and repainted so there are no side decals on the door and it is two tone like a z28. it had no dash emblem when i bought it and the driver door was replaced after the wreck and inside its a maroon color. under the hatch area plastic my car is silver also and i dont have the b4z i think is the iroc code in my rpos. its 305 tpi 700r4 tranny i dont know what rear end or gears but it does have what i have always thought was the iroc hood, iroc rear spoiler with the light in the middle, it has a roof console, fully loaded, 145 cluster, the dual intake box thing some people call ram air. thanks.

 

oh and yes it has fog lights in the front and the camaro grill. grid like lights in the back also if that matters.

 

B4Z is the IROC RPO. Your car looks like a regular Z28.

 

so is it not possible that its is an iroc without the b4z thing? EVERYTHING on the car is iroc besides the paint and rims. who would go to all the trouble to put the iroc stuff on a normal z28? i checked the vin at 2 different places and it says 1987 chevrolet iroc/z28

 

If no B4Z in your RPO's then no its not an IROC. Plus those wheels are Z28 wheels. The IROC Package was really only the 16 inch wheels, the wonder bar. the graphics package and grid taillights. I think there was some suspension changes from the regular Z28 but not completely sure about that.

The Hood, ground effects and spoiler were the same on both cars. As with the engine packages each car(Z28 and IROC) could have several different v8 combos, except of course the 350- 5 speed.

 

Kev,

Let me clear this whole issue for you. Appearance wise, your car shouts, "Z28". You have charcoal rockers, Z28 striping, and 15-inch Z28 wheels.

Now here's some history. For 1985 - 1987, the Z28 included a sports hood with louvers, color-coordinated rockers (in silver, gold or charcoal, depending on exterior and interior colors), specific four-color striping, grid taillights and 15-inch five-spoke wheels. Fog lamps were option in 1987, included in RPO 1SC (the most expensive option package).

The IROC-Z was an option package available on the Z28 (above). Functionally, this package included different suspension pieces, a "wonderbar", Delco-Bilstein rear shocks, and 16-inch wheels. Cosmetically, the ground effects were painted body color. Specific two-color striping was used and fog lamps were included.

Note: RPO's (regular production options) are listed in your center console storage box. The RPO for a Z28 is Z28. The RPO for an IROC-Z is B4Z. On IROC-Z's, you'll also see Z28 in addition to B4Z.

Also, examine the tire label sticker on your driver's door jamb. It will list the original tire size. In 1987, only the IROC-Z got P245-50VR16 tires. The Z28 tires were P215-65R15.

I've attached a pic of my 1987 Z28 convertible. Please note it does not have the original Z28 wheels. But notice the similarities in color-contrasting rockers, striping, and hood.

 

What is the RPO code for my '89 IROC-Z? Just want to confirm it even though it has the hood, ground fx, decals, spoiler, 16" IROC rims, wonder bar, and some other goodies. Since I don't have the B4Z, I am assuming this is only for the '87 model year? Thanks.

 

What is the RPO code for my '89 IROC-Z? .... Since I don't have the B4Z, I am assuming this is only for the '87 model year? Thanks.

B4Z was used from 1985 thru 1987. With the discontinuance of the Z28 from 1988 thru 1990, the IROC-Z stood alone for these years. It did however, use RPO Z28 (ironic, isn't it?).

Willie

 

I don't have the Z28 RPO code either. What's the deal here? I DO have a real IROC right? I have ALL the suspension and body things that would say it is an IROC, I also have the 350 TPI. Also got the borg-warner 2.77 9-bolt, and 4 wheel discs. Also, I do have the B2L "performance package" RPO code if that helps. Do I have anything to worry about here? Thanks.

 

Here she is:

 

my driver door has been replaced and is missing the stickers. i have the following rpos:

ac3, ag9, au3, a01, a31, a90, b34, b35, b84, b9k, b94, b97, cc1, cd4, c49, c60, dd8, de1, dg7, dk6, d08, d34, d42, d6d, d80, d88, e52, e72, e92, f41, gu2, g80, j50, k34, k68, lb9, md8, mxo, na5, nod, np5, n33, n65, n90, pb4, p20, qyz, tr9, tt4, t93, t96, um6, uq1, u21, u25, u26, u79, vk3, v73, yt9, z28, 1ay, 1pv, 1sc, 12a, 13q, 13o, 62x, 72x, 8nm, 82b, 82i, 82p, 829, 9mn

 

IROC-Z28's have RPO B4Z 85-87 and Z28 88-90. Without them it ain't an IROC-Z, there's no other way!!

 

I don't have the Z28 RPO code either.

Very strange.... but I don't know everything. Maybe someone else can shed some light on this.


....Also, I do have the B2L "performance package" RPO code if that helps.

B2L was available only on the IROC-Z, so I wouldn't worry any.
----------

f41....g80....lb9....mxo....qyz....z28....1sc

F41 = Base Z28 suspension (IROC-Z is FE2)
G80 = Limited-slip differential (a mandatory option with the 305 TPI)
LB9 = 305 TPI
MX0 = Automatic transmission
QYZ = P215-65R/15 blackwall tires (Used on the SC & Z28)
Z28 = (self-explanatory)
1SC = The highest level option package which included fog lamps.

There you have it. Your car is a Z28.

Willie

 

so the only difference in my car and an iroc is some rims and tires and some suspension parts? kinda ironic isnt it that you can get BETTER suspension parts and rims. so paint my car get some torque thrust 2s, some better sway bars and bushings and that is that right? its equal to or better than a stock iroc then right? or is this an ego thing where cause some people have 3 letters it makes their car so much more special? im curious how this whole thing works.....

 

Alright, thanks for the help Willie, I guess I need to go check it out more closely in the glove box. Hang on, I think I took a pic of it. Lemme re-size it, then I'll post.

 

Nope, nevermind, it was a very bad pic, so I'll check it out later I guess. Thanks.

 

so the only difference in my car and an iroc is some rims and tires and some suspension parts?

Basically. And the graphics too.


kinda ironic isnt it that you can get BETTER suspension parts and rims.

The front and rear springs for both cars have the same rates. The only difference is the IROC-Z sits 15mm lower than the Z28. Part of this is due to the tire size difference. Conjecture says the fractory workers who intalled springs into the IROC-Z were instructed to choose the shorter production pieces and left the longer ones for the Z28. Whether this is true, no one knows.


so paint my car get some torque thrust 2s, some better sway bars and bushings and that is that right?

The sway bars are identical. Personally, I like the look of the Z28. For 1987:

13,974 Z28's produced
38,889 IROC-Z's produced

I'd say keep your car looking original. BTW, the 1987 Z28 striping has long been discontinued and no one reproduces it (the 1985 - 86 striping is reproduced, not the '87). If you remove yours, you cannot replace it. Also, charcoal Z28 ground effects and wheels are rare. I owned a white '86 Z28 (bought it new), with charcoal and never saw another one like it, even when these cars were new. Keep it the way it is -- it's a rare color combo!

Willie

 

eeek!!!! i need the stripe kit i love it!!! guess i cant repaint it then huh? or can u repaint without removing the stripe kit? what suspension wise can i do to improve my cars handling? best rims and tires? anyone that can photoshop several different styles of rims on my car and email them to me?

 

I can't believe myself. I just went out to look, and there was good 'ol Z28 lookin right at me. I counted a total of 79 RPO codes, and for some reason, I only pluged less than 50 in when I was trying to decode the codes. I don't know why I left so many out. Oh well, that was when I first got the car and I didn't know what I was doing I guess....now it's time to go decode all those other numbers...yay!

 

.... or can u repaint without removing the stripe kit?

Absolutely. As long as the striping is in decent shape, you can mask over them. I know someone who did this on their '87 Z28 and it came out great!


what suspension wise can i do to improve my cars handling?

I don't know about aftermarket springs because I've never used them. As far as handling, stick with your sway bars (same as an IROC-Z) but use poly bushings. You might want to pick up a "wonderbar" off an IROC-Z and bolt it on too!


best rims and tires?

I like the IROC-Z wheel. That's why I have a polished/painted set on my Z28 (pictured above). I even went to the trouble of replacing the IROC-Z centercap applique with one from a Z28, removing all "IROC-Z" lettering off my Z28.

Willie

 

ALRIGHT ANOTHER HIGH OPTION 87 Z28!!

Your car is very much line mine... I have upper concole, fogs, auto dimmer rear view, split rear seat, grid tails, leather wheel **** and ebrake, 305 tpi auto and a host of other things... I upgraded to a 36/24mm front and rear set up.. i think the old one was 24 also, so i guess it didnt matter and went with poly bushings.
My car looks just like *******, only TTop, and stock 15's..

also, Ive had the car since new(dad bought it in 87)

 

Maybe.... just maybe.... if you don't have the IROC or Z28 codes... maybe your car is just a Z28 or IROC clone? Little chance, but you never know.

 

ok so now we have established that i have a high otioned z28 here. what would be the next step in improving the car? so if u bought this car what would you do? keep in mind im 17 so i cant do an engine swap or anything major like that.

 

Rims and tint would really enhance the car. You said you like the TT2s I think it would look good, or like Willie said the IROC rims would look really good as well, and probably cheaper than getting a set of TT2s.

 

can someone photoshop tint on my windows? i was thinking of doing that next to tell the truth. i was debating either a hooker cat back or tint and some iroc rims if i can get some. tt2s are like 800 and right now all i have is 250.

 

I don't know if this helps any... but in 1988 Iroc's were available with either 15" OR 16" rims... it was an option, and doesn't mean it isn't an Iroc if it doesn't have them... I should know! My 88 had the 15"s on it.