I want to put 17x8 wheels on front, and 17X10 rear (or 9.5).
The mechanic at the dealer told me that all around the backspacing
is 6.5...>7.oo". the wheels I want are re Billet Specialties GTX65
Their measurement sheet states for 17x8 wheels max backspace
is 5.375".( The rear is not a problem.) Is the mechanic right? Does a
95 Z28 with 255x50x16 have an offset of 6.5...>7.00"???
If so ofcourse the GTX65 whls will not do the trick.?????????




95Z28LT1A4: Racetronix fuel system, full race suspension(DRAG),
MSD Ignition and Billet Distributor; Battery reloc. Spohn front
upper and lower A-arms, upper and lover balljoints, and K-member
in Tubular Chrome Moly, 38lb.delphi/lucas injectors, Red/Black Ttop.
etc.etc.etc...too much to list...

 

Check the FAQ for information on recommended offsets for various width wheels. Note that "offset" and "backspace" are not the same thing. A stock 16x8" 4th Gen wheel has a 55mm offset. That corresponds to about a 6.62" backspace. A stock 17x9" WS6/SS wheel has a 50mm offset, which works out to about a 6.92" backspace. You can run close to 8.0" backspace in the rear, but will probably need to hammer the inner fender liners and/or cut the protruding edges off the jounce bumper brackets. 7.75" backspace is cleaner, for the rear wheels.

In the front, you can push up to 7.42" backspace with a 17" diameter wheel.... a bit more with an 18" diameter wheel.

A 5.375 backspace on an 8.0" wide wheel is about a 23mm offset, and that's going to put the outside edge of the tire pretty close to being even with the outside edge of the fender.

 

I have 17x8 with 5.5 inch backspacing on the front and 18x10 on the rear with 7 1/4 backspace.

Billet Specialities will want a backspace measurement when you order them.

here on a 94 z/28 also

 

So you have a 94 Z28 with Billet Specialties Whls? In their online cat.
GTX65 they list a max backspace of 5.375. Your offset/backspace must be same
as mine (95Z28) which is 6.5...>7. and they fit right? in the front tht is.
Thanks

 

No I have TTQ2's but the backspace will be the same for any 17x8 wheel, My wheels sit almost flush with the edge of the fender,