Will I have any issues going from a 33-12.5-18 to a 295/70-18 which is 34.5? I am running 2.5 inch coil lift, track bar, front lower control arms. Just want to make sure going up to that size won't cause me any problems or cause the need for more parts.

 

You will be fine. Might have some rub in the air dam or other plastic... Easy fix.
A lot of people running 35's with that setup.