I’ve been playing with the idea of buying/making some hub centric spacers so that I could run my 16” rears on the front (allowing me to rotate tires easily, I can tolerate the look of the front offset on the rear) and to space out the stock 15’s that I mount skinnies on when I go to the dragstrip (they just look awful tucked all the way in).

I figured, the stock rears are supposed to be 16mm offset (about 5/8”) and the 15’s are supposed to be ½”, so something in that range should work fine for both, till I measured them.

I found that one set of 15’s (firebird style, look a lot like my 16’s) had a 3/8” offset, and the stock “high tech” 16’s on my formula actually had almost a 7/8” offset. I suspect the second set of 15’s (some early 3rd gen TA “performance suspension” wheels) are also different, since at one point I noticed that the car had a slightly different stance on them with the same size tires, but I haven’t measured them yet. BTW, the 16” fronts were actually 0, as advertised

Has anyone measured the stock mesh rims?

Anyone play with this before? What did you end up doing? I’m not sure that I really want to space the 15” fronts out past 0 offset, but then again, I don’t think that the stock rear will fit right or look right with a spacer in the 3/8” thick range

 

I have run 4 "rears" IROC rims for years now and rotate them. I do have hubcentric spacers I had custom made.

I have no clue as to any wheel offset other that the fatory 16" rims being 0 offset for the "fronts" and -16mm offset "rears".
These were the front spacers I submitted to "MY" brake offset tolerances and to be used with "rears" IROC'son the front.

 

Here are the finished Spacers from EMachineShop.com before I pressed in the 1/2"x 2.970" ARP studs(Original GW 1/2" stud pictured still)

 

that thickness is within a few thousandths of what I measure that mine should be.

What did they cost from emachineshop? is the inner hub surface tapered?

 

They are aluminum and hardcoated ceramic black. Shipped to me they were $237 for the pair.

The insides are not tapered. you can see in the CAD drawings that the hub and sapcers both have a "step" in the center diameter. These are Global West aluminum G-body hubs, not 1LE f-body hubs.