RE: How to set prop for horizontal stop?
Better way (for me) is to loosen the prop nut, rotate the crankshaft counter clockwise so it just starts to come up against the compression stroke and tighten the prop nut with prop exactly horizontal.
Assuming the engine doesn't stop at TDC, the prop will windmill backwards until it hits the start of the compression stroke. This is where you want the prop to be horizontal.