67 Wheel fitment help

[67Rally]

Here's what I learned when researching tire/wheel combos for a first gen a few years back...

In order to center the wheel in the openings these are the best backspacing numbers (wheel diameter doesn't matter 15,16,17,18,19,20,etc):

Info for an 18" setup:
18x7 4.25" BS
18x8 4.75" BS
18x9 5.25" BS
18x9.5 5.5" BS
18x10 5.75 BS

225/40's will (almost) always fit up front with the right backspacing. 235/40's have a good chance of fitting without issues. 245/40's are pushing it and might scrub on the inside on tight turns.

255/40's will (almost) always fit in the rear with the right backspacing. 265/40's have a good chance of fitting. 275/40's are pushing it and might scrub on the inside if the suspension isn't tight.