Re: "How long, exactly, did you make the 2x4 pole?" ... for the home made mast self raising system.

It is a standard 8" 2x4. The attachment point on mine is about a foot from the end. You probably want it fairly far out to get more "lever" moment. On my setup the rope attaches about 7 foot out, and is in a straight line from the winch to the attachment point up the mast. IE, when building it, I tied the winch line to the point on the upright mast where I tie the winch line, then partially mounted the 2x4 and marked the attachment point where the line crossed the 2x4 "pole".

I recall now also that my "pole" is not directly perpendicular to the mast. It is tilted slightly higher to avoid the bridal "foil" on my Nacra.