Originally Posted by cbzzoom

So did you guys run 265/305 ? Like this ?

265/35/18 : 25.30
305/35/18 : 26.41

That's pretty close to the stock diameters :

235/35/19 : 25.48
305/30/19 : 26.20

but with a bit more rake.

One advantage of the 255/315 is the smaller diameter gears you down by 3% and lowers you a bit, but those are small effects :

255/35/18 : 25.00
315/30/18 : 25.44

It seems maybe 11.5" rear is actually the more general purpose size.