New 15 in. 15x8 Rear Wheels And Tires For Dads 72 340 Duster

My Father Is The Original Owner Of A 72 340 Duster.
The Original 340 Has Never Been Redone And He Decided It Was Time Being Tired.
Doing Some Internal Mods But Nothing Crazy Will Be More Powerful.
That Thing Always Ran Great And Did'nt Even Think Of Hooking Up Then.
He Wants To Get A Good Drag Radial But Nothing Is Available In 14in.
Time To Replace The 14 in. 5x4 Bolt Rallys With Some Rear 15x8 4.625 Backspace Wheel by Wheel Vintiques
Has Anyone Used These On A Stock Duster With No Quarter Panel Or Spring Mods?
Thanks In Advance
Mike Z.

if you still have 4 inch small bolt pattern.
you will need 15x8
4 1/8 backing space or
4 1/4 backing space
no more tire may hit the spring
i run 275 60 15 tire with this size rim i mention.

I'm running the 15 X 8 rallies with 275-60-15 on the rear with no problem, and 15 X 7 on the front with 215-65-15. All four rims have 4-1/4 back space

i bought 15 x 8 small bolt with 4 1/2 backing space with 275 60 15 tires and they hit the spring.

if you have large bolt with 10 x 2 1/2 brakes than 4 1/2 backing space will work perfect.

Thanks Guys They Look Good On Your Cars Surely Fills Up The Big Wheel Wells.
Mike Z.