I had never noticed it before but I recently found that a set of 1988-1990 wheels I bought had different size lettering for "front" or "rear" wheel logos from each other. I had 3 different wheels out of the 4. I then noticed that on one the valve stems were placed opposite the "front" designation on the wheel and on another it was 1 spoke over from "front" and on another it was 2 spokes over from the valve stem. At first I thought that maybe the valve stem hole was drilled out randomly on the wheels at the factory. Then I looked at the only set that I knew were originals on my 1989 and they were all drilled opposite the "front" or "rear" logos on the wheels. Does this mean that since I've found 3 different designs they may have changed it each year for 88,89,90?
This got me more curious so I looked at sets of 1985-1987 16" Iroc wheels that I have. I found that with the 4 complete sets of these years that I've got there was also 3 different placements of the valve stems and different "front" and "rear" logo sizes. I've had these wheels for years and never noticed these differences. Has anyone else noticed this or know anything more?

 

Never noticed something like that, but it could be they changed from year to year or it could mean they were made by different vendors.

 

It's possible for more than one wheel supplier, or at least one east coast and one west coast supplier. I honestly cannot answer if any of that is correct, but I believe these wheels were cast, so unless the mold(s) broke, most of them should be identical. Can't really explain the reason for the differences

 

The main difference is the location that the valve stem hole is drilled in the wheels.
The other difference that I noticed was the letter size for "front" and "rear" on the wheels. Anybody else have these variations on their 1985-1990 Iroc 16" wheels?

 

Interesting observation. I'm going to check my original '89 Iroc set in the morning.