27 inch tires on front of 70 duster

[71dustya]

I have a 70 duster with aftermarket front brakes. Was wondering what size front rim and back spacing do i have to go with to get a 27 inch tire on the front. I have a 15x4 with 1.75 back spacing now and cant get 27 inch tire on without rubbing. Any help would be great thanks

 

[AdamR]

These are 205-70-15s on 15X5.5" centerlines. I dont remember the back spacing. I had a 215-75-15 on them before.