heres the stretch ratio of the tire sizing you wanted. any ratio between 5.8-7ish will give you a nice 45 degree angle stretch for clearance. this formula works well for 18-19 diameter wheels. Basically if you look at your current 265.30 vs 245.35 and already knowing how your stretch looks with 265.30 on 10.5. now look at the ratio for the 245.35 ...its goona run taller with less stretch angle. personally i would prefer the 255.30 and go from there. but this would also depends on the stretch on the front for a matching look.
You can get some stiffer bumpstops or run a stiffer rate spring if tires alone didnt fix your rubbing issue.
245x.3 = 73.5/10.5= 7 ratio
255x.3 = 76.5/10.5= 7.2 ratio
265x.3 = 79.5/10.5 = 7.5 ratio
245x.35 = 85.75/10.5= 8.1 ratio