personal experience
just to let you know, a zq8 with 2" spindles, 18x9's will not work out, at least in the case i had. i was workin on this truck and i got everything put on, and put the wheels on, went to back out, and it wouldn't move. i looked at it for a while b4 i wrecked anything, and i realized that the spindles were digging into the edge of the wheels. I run an 8.5 on my truck and i cant even get a finger in between my spindles and the wheels, so it is a very close call there, and i didnt think about a half inch mattering. this may not be the case in all situations, but its just a warning.