Im new to boat ownership and already buying a new prop , my question is I don't understand anything about sizes or LH ??? Im looking at this one I found online and wondering if it would work for my 3.0 mercruiser inboard https://secure.gandermountain.com/modperl/product/details.cgi?r=view&i=71290 ..... Please let me know if this should work for what I need , I don't want to screw up and order something that doesnt fit or doesnt work correctly ...thanks in advance