I bought a used one about 10 years ago, not knowing it was a reverse PTO model, and it did have the 18 spline female pto. I had a parts deck that was my father's and was the correct rotation. Swapped the pto shaft and took a blade with me to order new blades. I started mowing and the blade bolts would not stay in. Swapped spindles too and fixed the problem. The blade bolts for standard pto rotation are left hand thread.