The tractor PTO turns clockwise when facing and the gearbox on the cutter, counter-clockwise by design. Originally, the spline seats at the rear, and probably poorly machined, bearing accommodations before an oil seal and the facing drive gear was at the forward side, turning the horizontal beveled gear counter-clockwise. By moving the drive gear to the rear, the horIzontal gear turns clockwise and accommodates the proper direction to utilize the Gatorblades. However, since there is no longer the resistance created by the distance of a frontal orientation and the spline seated at the rear of the gearbox, the spline has slightly forced itself askew. If I turn the gearbox around, which I can because there is a spline seal on one side and an oil cap on the other, it doesn't resolve the fact that the drive gear still turns counter clockwise and must be at the rear of the gearbox. So you're correct npalen and I agree, I thinks it's our tolerances in the casing. Spacers at the front spline seem to be the only possibility.
BrinkME:
I'm still wondering exactly what kind of damage I might suffer just leaving it the way it is as I don't see an immediate resolve and refuse to live without my Gatorblades. I've got Royal Purple Synthetic gear oil inside.
kthompson:
This finish mower is one that Doosan had made when they briefly sold Kioti tractors under the Bobcat brand. The mower is not a Kioti mower but was one made to their specifications. The blades I sized top match address made by Oregon, famous for chainsaw blades, and address the Gatorblade brand. These address sized to match. In other words Gatorblades address made specifically to many, many mower's but sometimes you have to size them. I used to have a Kubota BX2230 and found identical dimension blades but have to utilize a reducer for the center mounting hole. All Gatorblades are same side cutting edge and cannot be b'way flipped by design. Google them and you'll see.
Thanks all!