well, if you just flipped the axle 180 degrees and bolted it back in, then yes....you would have one forward gear (reverse) and 3, 4 or 5 reverse gears (depending on how many forward speeds your truck has). The DS is spinning the same direction, but now the ring gear is on the other side of the pinion....if that makes any sense to you.
HOWEVER, if you cut the spring perches out, set the rearend on new spring perches with the pinion angle set right, then welded the perches on to the axle...and then bolted all that down onto the springs...you have a lowered rear end.....without flipping the axle 180 degrees.
