general tire fitment

[steve40]

so i kinda have done things a bit backwards. i had a 9" housing in my car, and have come to the point, that it's easier and probably the same cost to pick up a housing and axle package vs fix everything i see wrong with the one in the car. i have wheels, tires, and all the brake components. when talking to a shop about a housing, they mentioned that while filling out their form, housing width was to be specified. i wanted to know if there was a general rule for clearance needed between the tire and body on the inboard and outboard sides. i have a 84 monte ss, so it's a full frame car. the body is untouched, the frame has been notched, the body is the limiting factor in width.