i'm thinkin about getting 18x10.5 wheels in the back with nitto 305's, and getting 17x8.5-9.5 with nitto 275's in the front with z06 wheels with chrome rivets. how does this setup sound?

 

the 18x10.5's wll have a 58mm offset and the 1x9.5's have a 54. will this mess up any gravatational pull etc.? will it work with the different offsets?

 

The different offsets are required to locate the wheel/tire correctly within the fender space. An 18x10.5 58mm offset wheel has approx. an 8.00" backspace. That will put the inside of the wheel very close to the inner fender, similar to running the popular ZR1 17x11 50mm offset. Whether the tire rubs will vary from car to car.... maybe 50% of us have to hammer the inner fenders and the other 50% don't.

In the front, the 17x9.5 54mm offset is fairly common.

As long as you keep the wheels "centered" in the fenders, you aren't going to end up with any oddball handling problems or "gravitational pull". I would think that using the narrower 17x8.5 wheel and narrower tire in the front, rather than the 17x9.5 would cause a bigger upset than the small difference in offsets front to back.