Starting a BB Duster project

I think it is 50 1/2 inch from rotor to rotor. It has disc brakes on it so that adds a little extra width.
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I'll go back and re-measure mine. The 60 may be a bit longer than the 8 3/4 in my car..I'm going to run the M/T 31×18.5×15's..The rear discs on mine are SBBC..What brand is on the 60?.. It looks like a very nice and new rear end..