alright im thinking of buying 3 chrome 9.5 zr1's off of someone local, he said they came off of his ss, but they dont say gm anywhere, does that mean that they are replicas? also i asked waht the offset of them were, he read the back of them, one said "56mm", one said "50mm" and the other "54" with no "mm" at the end, do you think the 54 is not the offset and maybe something else? if thats not the offset , anyway of finding out what it is?whats a good offset for the zr1's on camaros, would the 56 go on the front or back, 50, front or back? do you think that if the "54" is a 54mm, that a 56 and a 54 together would be ok? then 2-50mm for the other pair? hopefully that wasnt to confusing, please give me your thoughts, thanks

 

Couldn't tell you whether or not they are replicas, but I'm sure someone will know.

As far as offset goes, a wise man called Injuneer once said....

"In general, people limit the front to 9.5" wide (40-56mm offset range), and the back to 11" wide (45-50mm offset to keep the tire under the fender)".

Good luck.

 

I'd be a bit concerned about the wheels and where they came from. An SS would not have come from the factory with 17x9.5" wheels. Although the stock SS wheels look like ZR1's, they are only 17x9.0".

The best offset for the factory ZR1 wheels are the "Grand Sport" offset wheels, and they are 17x9.5" 56mm offset. While anytihng from 40-56mm will "fit", I would not put three different wheels on my car. They should match, at least both the same in the front and both the same in the back.

The best thing you could do would be to measure the "backspace". Put a straight edge across the edge of the rim, and measure straight down to the face of the mounting hub flange. That's the backspace, and they should all be the same. A 17x9.5" 56mm wheel has approx a 7.41" backspace. You have to measure very carefully, since a 2mm change in offset will only make an 0.08" difference in backspace.

 

mmm.. his came off of an ss, but they just dont say gm, i should have probably have said 5 spoke ss instead of zr1's, but im going to go pick them up right now and i'll bring them home and hopefully i can figure something out , i'll check back with whatever i figure out,
please check back injuneer, i appreciate them help

 

mmm..well i gotta say im confused, i got them.. one of them says 50mm. another says +54 2.788 or something like that, and thats on the lip of the rim on the inside.. another says 56, but then on the outer rim part(the part that would usually be covered bythe tire) it says 65mm. and it has the date of xx/xx/2004, wtf? ha is that one a 56 or a 65 i picked these up for $150 lugnuts/covers/locks etc, he said one was flaking, ha, one is flaking badly on the outer lip, the other is flaking a little bit on the outer lip, and they all are flaking on the inside, is that still pretty bad if there flaking on the inside?? it looked like mud but i got home and it was chrome flaking, aaaaaaaaaah did i get ripped off?

 

If you just have the wheels with no tires grab a scale. The GMs are forged and should weigh about 20-21lbs/wheel...replicas are cast and weigh as much as 27 lbs each...

--Alan