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1970 Mopar B Body looking for info on wheel back spacing and tire choice


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Apr 4, 2023
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Santa Clara
1970 Mopar B Body looking for info on wheel back spacing and tire choice
Did QA1 upper control arms upgraded torsion bars and rear hemi rear leaf springs from Mancini racing looking to run front 15x8 Mag wheel with a 4 1/2 back spacing with a 235/60/15 tire. In the back looking to run a 15x10 mag wheel with a 275/60/15 Jegs telling me this set up works. Any real time actual experience welcomed does this sound correct to u guys thanks for your time and input
There's a few different 70 b body wheel wells, what are you working on.
Mopar Joe uses 15x8's with a 255-60/15. I don't know what he uses on the front. 7" standard offset but no clue on tire size.

Joe's bee.jpg
you could go to a P295-50-15, 12"-ish of girth, 28"-ish diameter
on the back fit good, look good too
on a 10" wide wheel, 5.25-5.50" (IIRC) backspacing
(don't take it for granted do the measurement yourself)
you could do check with a 18"x 24" builders/carpenters square,
or a good straight edge & a tape measure
measure from the face of the brakes where the wheel butts up-to
back to the springs & the other direction to the wheel lips
if you go too tall or too wide, the tires
it will rub at the top of the inner wheel well
on a hump inside on the outside of the inner well
or on the lip/trim edge

welcome to FBBO from NorCal Sierras

good luck
I have a 275/60 on a 8" wheel, with 4" back space, and they rub equally inside and out when the car is loaded pretty heavy and maybe driven a little aggressively.
However I have a '66 B body housing, which is a little narrower than a 68 housing.