I have the same prop here at the house. It is a MICHIGAN WHEEL 13 3/8" X 17 pitch for an OMC V4 gearcase. Fit's almost all of the V4 JOHNSON and EVINRUDE 2 strokes, and some of the 3 cylinder 2 strokes. It would be a bit much prop for a V-20 with a V4 though I think. I ran mine on a 19' bowrider, ran close to 46 at 6000.