20 x 9 front +37mm
20 x 10 rear +38mm

What kind of tire size would I need for these? Is the offset ok for an '05 Z? Also, I have an Eibach Pro Kit on the way to me. Would I rub at all with this drop and this size rim?

 

Offsets are too high and your wheels will looks sunkin in

 

I would be looking for a offset in the low to mid 20's

 

Instead of guessing, how about using a offset calculator?

http://www.1010tires.com/WheelOffsetCalculator.asp

 

I concur. Offset calculators are the best.

Take measurements
Calculate
Take measurements
Calculate
Take measurements
Calculate

Sometime's it's also better to input your tire width if you are going with oversized race tires. Since that will be the widest point rather than your wheel.

 

I agree with Mike and davidv.....do your homework. I had those offsets and it did NOT look "tucked in." Check it out. Tire size can make a diff.