I am getting ready for the power tour and have a set of 17 x 7 with 4" bs and 17x8 also with 4" bs.T he tires are 245/45/17s front and rear. I would like a slightly taller tire on the rear. Should I go with a 255/50/17 on the rear?How about a 255/45/17? Need help quick! Need to get them right away . By the the way this is for a 67 RS.