Don't know how my IROC ended up having 4 REAR rims on it but it has.

I have spacers made up on the front ones. The rears also have spacers but from what I have heard that is normal and they all have spacers on the back??

Well since I have 4 rear rims on the car I thought I could simply rotate my tyres. Hahaha like always something has to come up. I changed the rims around and thought beauty all done.

But nope the front right rim hit the strut lip and if I drove it like that I would have taken off some nice material along my rim.

I thought to myself WTF??

Took the RIMS back off and what do you know that RIM was a 16x8x20!

All the rest of the rear rims are 16x8x16.

I emailed GM about this asking if they had different sizes for the IROC rims but I never heard back from them. So I have to run that rim on the back.

Anyone else have a rim size of 16x8x20??

 

It would have to be a aftermarket rim. The biggest back then was 16X8.

 

You have ONE 20 and you didn't notice till now LMAO.

Well it's not common and not stock I can tell you that.

 

Why are you laughing at that I have not noticed it. I can tell you right now you would not be able to tell the difference either if you did not read the back of the rim.

 

Hmmmm? 16x8x20 ??? Where does the 20 measurment come from?

 

I don't know where the 20 measurement comes from but it has something to do with the offset.

 

I do know that the front to rear have different offsets but I dont think rear to rear have different offsets. I havent got a clue?

 

You can run front rims all the way around, but they will stick out farther on the back. Can't run backs in front because they will rub.

Seems someone pieced them together for you. Thats to bad.

 

Well I found out from someone that the 20 means a 4mm bigger offset then the 16. It is a bit of a bugger.

 

only thing i can think of is one of your rims was replaced. i believe there was a different rear wheel offset for irocs and z28s with 16 inch wheels and disc brakes or drum brakes. that would be my only explanation for it.

 

Many Z-28 Irocs and IROC-Zs had rims marked as front and rear. Why GM did this I dont Know, but if you search on ebay you can find the correct rims for both the front and back. Or else try contacting WWW.fparts.us they can get you the propper rims for either the front back or both as can www.thirdgenresource.com