These came off of single-vein 16" IROC wheels on an '87. The cone part is solid aluminum, the other two pieces are the backing plate and bolt, which clamps on from the backside of the wheel. I have the entire set, I just grabbed a pic of the front two. It seems like a very good design. Much better than the stock GM clip-type. Is this an aftermarket deal, or what? Has anyone ever seen these before? Thanks, Aaron

I've never seen them...you wouldn't happen to have a pic of them on the wheels?

I can grab some tomorrow. Everything is kinda torn apart right now.

Looks like someone got tied of lossing the plastic ones and made some of his own. I had plain center caps on my 17" wheels and had IROC-Z decals made for them.

Those are aftermarket. I cant remember exactly but early/mid 90s classic industries used to carry them. Theyre rare to come by now. Good find.
Matt

Id like to see what they look like installed.

Crystallite engineering sells those also in back eighties.

Cool. I'm glad at least somebody knew what they were. Here's a couple of installed pics. Don't mind my dirty unpolished wheels:

Looks a lot better than I expected.

not to steal this thread but i was wondering if anyone could tell me why the rims are stamped front and rear (you can see this in the first pic). I called the local chevy dealer and they had no clue lol

rears go on rear front on front they are slightly different offsets. 0mm and 16mm i believe

anyone know if anyone still sells these? i think they look pretty cool

If they came in a flat version, I'd get 'em engraved with IROC-Z. Subscribing just in case anyone finds a current vendor of 'em. I don't wanna shell out $50 per cap to replace the two missing centercaps on my car.

Those would be super simple to have done on a CNC machine. The cost to do one (or just 4) wouldn't come out very cheap, due to machine set up time & programming. But to make a dozen sets, to resell the extras, it wouldn't be real bad.

I'd prefer they had hex head of the stock later style (the big hex head) from 91/92, I think. Or just flat with IROC or Z28 machined letters into them.

Very easy to make.

If I made a Solidworks for them with the right dimensions, then it wouldn't cost as much to have CNC'd, would it?

I have no experience with SolidWorks, so I can't say much on that specificaly. We always programmed from paper drawings & dimensions.

But if SolidWorks could Export the file into a format that the CNC machine could use, that would save them a LOT of time. That's how I do my vinyl decal designs. Simply export them to a USB Flash Drive & the shop Imports them & can cut them within 5 minutes.

I have those center caps on my car. I like them better than the plastic factory ones. These were on the car when I bought it. I've seen them for sale on ebay and other car part sites.