How do I determine the size of my propeller for replacement. The outboard is a 1985 Mercury In-line 6 cyl, 90 HP. There are 3 sets of numbers on the prop housing itself, and the letters D.A.N. which most people I Talk to don't have a clue as to the numbers or the Name?? My prop was broken, and I cannot determine the proper pitch, diameter etc for a replacement(yes I am a newbee). I have searched a local boating store and also numerous web sites with no luck. Any help will be appreciated.