I have a 1972 VW bug and am trying to put on 18" wheels but I dont know what offset I need. The front of the car will have 2" drop spindles as well as disc brake conversion. All four fenders will be 2" wider fat fenders or I can go with 3" if needed. Can anyone help me with what offset I need? Like I said I want to go with 18" but I can go with 17" if needed. I'm also assuming I will need rear wheel drive wheels.