I have a five ft. Super Sunshine Modern Welding Brush Hog. It has a Omni Gear box Series RC51 Assembly #250746 date: 080111. The equip. gear box shaft has a 1 3/8dia x 5 1/2" lg 6 splined shaft. Question: What Power Take Off Yoke do I need for this cutter? Also, because of the 6 Splined gear box shaft, am I restricted to a clutch type pto or is there another type that I can use with just a shear pin?