Putting 325s out back?

275/50/15 no muss no fuss on a 8" wheel w/ 4.5" backspace on a 70 Duster. Springs in stock location. They are about 1/16" away from spring clamps. Gonna run a 1/4" spacer...little wider than a 275/60 and only 26" tall so you dont loose any gear with a tall 60 series tire....low and mean looking too! I never was one for a real tall tire on the back of an A-body...