i only have one prop i want to buy another used one or new one for back up what do the numbers on my prop tell me what it is here are the numbers on prop 48 78122 A40 21P. when i look up props they don't have the same numbers to campare to. i'm assuming the 21P means pitch what do the other numbers mean. as mentioned in the title 1983 470 merc
what was the standard size they use on this motor the gear ratio 1.84:1
what was the standard size they use on this motor the gear ratio 1.84:1
