(Im building a wide body 2000 ls )(need help)

[Curtis]

I have 245/40/18 on 10.5 wide wheels on front with 1.5 inch wheel adapter spacers and im going to try to run ether a 245/40/18 tires on back or a 255/35/18 tires on 12 inch wide wheel in back the question is has any one cut rear wheel archs on body of car too give more clearence or rolled rear fenders or would adding stiffer and taller bump stops

help with no rubbing