the stock diameter for a 305 is 305/45/20. Will be just as tall as stock, but 12 inches wide. I have 275/55/20s on mines, but will probably go to a 265/50/20 this next time to get me back to stock height, cause I'm sick of my speedometer being off (2 speeding tickets when I thought I was close to the speed limit). The 305s would look awesome in the back, but i'd get a stock width tire in the front so it steers better