The mount will reach just fine since the backspacing is less. I wouldn't keep the spare on there long, but it "should" work for a little while. I ran a 31" spare on mine for a couple months.
92 YJ, 4.0, D44/60, 5" BDS springs rear, SOA front, 1" booms, 1" BL, 35x12.50x15 MTZ's, 4.10 gears. It's never done though.