Tire width

Stock spring set up and stock 5.5 inch wide 14 inch rallyes (or if you want to be correct for your 69 - 5.5 inch steel wheels that came on GTs) take a 245-60-14 tire with no problems. Plenty of traction for your/6... I think BFG TA radials are the only easily available source. A set of 205-70 14s on the front will have close to the same sidewall height for the front.