i've read the archives,just want to double check before ordering new wheels.current wheels when mounted came right up against outer wheel lip,so i want to move the wheel in,taking tire off rim(rim measures 11" high when laying on bench),put a level across the back,measured from the bottom of the level to the back of the rim(part that sits against the brake drum=3 7/8",so to move the outside of the tire closer to the inner fender well and away from outer lip about 1" i would want this measurement to be 5" back space,so i would order a 15"x10" by 5"? is this right? 70 runner and 70's s/s crager rims. thanks you and hope this makes sense.

Sounds right.

If you have almost 4" now and want an additional 1" then 5" is correct.

You might want to make sure the rim and the tire will clear the leaf springs. Too much backspacing can also cause the backside of the tire to rub the wheel wells when turning hard.

air in the tire when inflated might make it wider and fatter..

thanks AAR,when tire was mounted and inflated,it would just rub the outer wheel lip,which was not a problem with the old rotted out 1/4's as there was plenty of room then,so a 5" backspace would move the rim in and more center,i just wanted to be sure since once you buy new rims you kinda own them