I thought the axle that the prop spins on my be special shape(square,spline shapped) If i can just get any 13.5x21 and it will fit that is great. Sorry if I asked twice, still getting the hang of this internet thing.
Rather than asking for specs for the prop, you should have asked if the prop you are asking about will fit your engine. Since I don't know what engine you have I can't answer that question. I can tell you it is a Mercury prop, 13-1/2 inches in diameter with 21 inches of pitch. That is a very common prop for mid range Mercury outboards 75 HP and up.
thanks silvertip, you are and abundance of info. How do you think you learned so much about boats? I bet you asked alot of questions when you first started out? Besides, the only dumb question is the one not asked. Im going to try and find more info on motor, all im sure of it is a straight 4 cylinder, 1972 merc.