with my old 72 super i had 175 60s up front, they were on 4.5 inch wide chromies, the 175s were very close to touching the spring, so i couldn't go any wider, with a 5.5 inch rim you could do a 185 or 195 tire up front. i found that skinny tires like a 135 or 165 made the front brakes lock quite easy, a wider tire will help you stop and corner much nicer. especially when its wet out. when you lower your car, you cant go lower then two inches unless you get the bump steer kit, wich is some extra time and $$$ my car was only lowered 2 inches, if you go more your centerlink will be laying on the underside of the car, and your tie rod bars will probably bend up. also another thing you need to do when you lower your car is grind the bottoms of your tie rod ends, cause they will rub on your rim, well they did on mine, wich were 4.5s mind you, your 5.5 inch wide rims might be ok.