Wheel fitment with e body rear

Here goes another wheel fitment question that will prob be answered by 72blunblu .... I have researched an posted an came to the conclusion with the help of 72blunlue that I needed a 68-70 b body rear an 1/2 offset hangers to fit modern day fr500 wheels but I cant find a housing nearby for the past 6 months an now with everything goin on cancelled carlisle trip, But can get a e body housing near by .... So my question is what kinda backspacing would I need to fit a 18x10 wheel with 275 or even 285 tire on back of 72 duster ... I seen just recently where a member fitted some fr500's on his duster an they look great.. So my questions is do you think these would fit or will I need need backspace ? or can the idea an wait for a b body housing ?

Mustang Deep Dish FR500 Style Black Machined Wheel - 18x10 - Rear Only (94-98 All)