According to information that I have seen on this site, 1988 was the first year that the IROC came with 15" wheels and one had to order the 16" wheels to get them.

I have a 1988 IROC and it has 16" wheels. I have decoded all of the RPO codes and none of them translate specifically to 16" wheels. What would the RPO code be for this? Assuming that I don't have the RPO code for this, how could the existence of the 16" rims be explained? Dealer installed?

The reason that this is important is that I am going to purchase some aggressive shocks (Koni or Bilstein) and the part numbers specifically call out 16" rims. Is there some difference in suspension as well?

Thanks.

 

N96, can't help you out much more than that though, except that i know you could get an IROC with 15" wheels atleast with the TBI.

 

Look for RPO N96 and QDZ.

N96 - 16" x 8" wheel
QDZ - P245-50VR/16 tires

------------------
Willie

Supercharged 1987 305 IROC-Z, Daily-Driver, Emissions-Legal.
Former Paxton (6-psig) with 50-hp nitrous: 12.043 @ 112.86 mph.
ATI D1SC (10-psig): 12.056 @ 116.62 mph.
All stats are altitude corrected for 3,100 feet using NHRA's Altitude Correction Table.

http://willie.camaro-firebird.org/

1987 "20th Anniversary Commemorative Edition" Z28 Convertible -- Super Chevy Show Class Winner, 1998.

 

Wouldn't the spring codes be different as well?

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'86 Camaro Sport Coupe and '88 IROC

 

No dice on the RPO codes. Don't have either of them. That's the puzzling thing.

If, indeed, the spring codes would be different, then I may need to be careful here. Here is a list of RPO codes related to suspension that I have:

FE2 - Suspension System - Ride Handling
6ZW, 7ZW, 8NL, 9NL - Related to "computer selected springs" for all four corners

Nothing on tires... What's up with this IROC?

Ooops. Forgot to mention, this is a 5.7 (L98) IROC. Did the L98's come with 16"?

[This message has been edited by KeithO (edited August 19, 2001).]

 

My '88 IROC came with 15" wheels and they are rpo code N90. Might check for that one.

I don't know if your concern is originality or driveability. In case you were worried, you can run 16" wheels and tires even if you originally had 15" wheels. I've been running 16" IROC wheels on my '86 sport coupe since '88 with absolutely no problem. Only gotcha I ever ran into is that the 16" wheel steering box has a stop so that the tires don't rub on the sway bar. Wasn't ever a real problem, but I upgraded my box anyway. Upgrading (if you originally had 15") the shocks to the ones you want shouldn't pose a problem.

 

Maybe they were changed??

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89 RS

STILL Looking For:
An 87 IROC-Z28 350 TPI

 

I guess my only concern is that the new shocks will be valved assuming a certain suspension geometry. Since my car doesn't have the RPO code for 16" or 15", it is unclear what came with the car. I can say that these are correct 16" wheels for an 88 IROC though I can't figure out how they got there.

I suppose I'm just being paranoid since I noticed that Koni calls out specific shocks for the 16" wheels for this model year...

 

Cna you look on the door jamb and see what tire size it was originally equipped with?

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I WOULD RATHER PUSH A CAMARO THAN DRIVE AN IMPORT

1983Z28 350w/ edelbrock performer RPM power package , dynomax shorty headers, 700R-4 with shift kit, 750cfm carb, edelbrock 3" exhaust system, 16" IROC rims and ASCD SS hood.

future mods:
SLP headers, completely done over suspension, black paint with flames, NEW PLAN IN THE MAKING:
BUILD A WILD CHEVY 302 JUST LIKE THE ORIGINAL Z28 HAD

 

Look at the driver's side door. I believe a placard there should tell you tire size and inflation recommendations for that particular car.

JamesC

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[This message has been edited by JamesC (edited August 20, 2001).]

 

What "N" code is listed on your RPO sheet?

 

Now I feel stupid. I checked the sticker on the door jamb and the tire size is P245/50/R16. Then, I checked the "N" codes and discovered N96 on the console sticker!!!!

I wrote down all of the RPO codes (or so I thought) when I bought the car and updated them as I figured them out. I think I missed a few.

*** I feel dumb!

16" it is. Sorry for the wild goose chase.