what backspacing is needed to fit a six inch wide wheel under the rear of a 73 dart? i know i need to measure it and i probably will but can someone enlighten me before i go to the trouble?

If you have a stock rear end, then you need about 4" backspacing to put the wheel pretty much in the center of the well. You can get away with between 3" and 4.5" backspacing on a 6" rim if that's what wheels are available and depending on your tire width. A 6" rim is pretty easy to fit into an A-body wheel well.

I have 8" wide rims on my '64 Dart and '66 Valiant. That's a little tougher, but still fine. Have 7" wide on my '68 Dart with 4" backspace.

Personally, I don't trust anyone's recommendations. I just measure everything at least twice using my existing wheels, and then get some wheels that will fit...

Lou

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Home of Slant6-powered fun machines since 1988

how do you measure for back spacing? i have 15x7 wheels from discount and have a problem with the right rear tire rubbing on the the inner fender on hard right turns i have looked at the spacing and i still have about a 1/2" to 1" of clearance between the tire and the leaf spring. if i have 3.5" of back spacing now, does that mean 4" of back spacing will move the tire in 1/2"?

zedpapa

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1970 dodge dart w/225 /6 bored .040" over, holley 390cfm w/vac. sec., compcams 252s, clifford shorty headers w/2.5" exhaust w/flowmaster, f-body 11" front discs, aluminum A-833OD, 8 1/4 w/3.21 SG
soon to have 5 gears!!!

Yes.

Backspacing is the distance between the mating surface of the rim and the inside/backside bead mating surface.

-S/6