a board member had '01-04 mustang 17x8 rims on his '69 RR using 3/4" thick bolt on spacers (makes for 5" effective backspace) all the way around and 255/50R17 BF goodrich KDWS's and they fit fine. I have the same setup on my 5th ave

1976 Spinnaker White Plymouth Duster, /6 A833OD
1986 Silver/Twilight Blue Chrysler 5th Ave HotRod **SOLD!***
2011 Toxic Orange Dodge Charger R/T
2017 Grand Cherokee Overland
2014 Jeep Cherokee Latitude (holy crap, my daughter is driving)