Want to put an early B body rear into my 69 Dart (because I already
have it, it's cheaper than getting an A body rear, and it has the
big bolt pattern)
What is the biggest 15" tiree ican fit in the stock well and what
backspacing do I need to order on the rims?
(approx- I know it will vary slightly from car to car)

The B rear is probably 1.5" wider per side than an A rear. As far as you tire sizes, put the car up on stands and hang plumb lines down from you narrowest points. That will give you an idea of how wide you can go. For wheels, measure from your drum face now back to your closest point (which should be your spring). Allow for the width of the sidewall and go from there. Just as a guess, I think you should be able to get a 245/60-15 on an 8" wheel with about a 5.5 backspace.

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Official Cookie and Mater Tormentor.

Might be a good application for some new Mustang rims. They are 17x8 with 5.72 backspacing. I know of several guys running those on A body cars with B body rear ends.

as andy points out the mustang rims should work. i took some measurements and it appears the '70 down rear will work with those wheels. plus they are about 100 bucks cheaper than most 17x8s that have stock backspacing (ex. american torque thrust.)

-james

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