71 Duster rear wheel and tire combination help

I have 275 tire on the back of my Duster and they fit fine . The ralley wheels are a 15X7 with a 4 1/4 rear spacing with a 1/4 spacer for spring clearance

Yours looks really good. Since the back spacing on the15x8 is 4-5/8 think I would need a spacer?