I just purchased a set of 19" Purners. For the rears, the only choice in Pilots is 345/30s. For the fronts, you can get 275/30s or 285/30s. Everybody I asked said the 295/30s would not work for the front. I went with the 285s, for a slightly taller front tire.
Even with the 285s, there is an overall difference of 1.375" between the two sizes. (Acutal measured height mounted on 10" and 13" rims: 25.875" Front and 27.25" Rear)