I've now got 2 sets of Z06 wheels sitting in the garage. The first set i picked up for $50 in PA, no tires. One of the rears has a pretty good sized flat spot on it from a spin out where the tire rolled off the rim. I picked up the 2nd set this past weekend locally with one front and one rear curbed with no tires, the other side in perfect condition with tires. Here's my question: both have different markings on the back. The set i picked up in PA have "GM" and the rim size info stipled/dotted on the back of the spokes. The set i picked up this weekend have "Speedline" and the rest of the info cast into the back of the rim. Does this mean the 1st set i bought are aftermarket? I don't really care either way, but would like to know for sure so i can list the extra set i have accurately. Thanks...

 

Marked GM= OEM GM Wheels
Speedline= Aftermarket Wheels

 

This is what the back of one set looks like. Marked both "GM" and "SPEEDLINE" inside the oval shaped castings. The other set has the rim size and "GM" marked on the back, but looks more like someone did it with a punch, dotted.

 

What else does it say on the Speedline wheel?

Good chance that both of them are factory Z06 wheels. They changed suppliers at least once. I'm looking for a couple more of the rears, so let me know how much you want for them. I'm local so I can swing by and pick them up.

Email me at austingerding (at) hotmail.

 

Correct.

The 2001 Z06 used forged wheels made by Alcoa. The 02-04 Z's had cast aluminum wheels made by Speedline.

 

That makes sense then, as one set's off an '01 and the other an '02.
I'll shoot you an email BIG_MODS...i even took pics this weekend.