Brand new to this site. Also new to trawlers. Have been a power boater for over 50 years. Currently own a 1973 Post 40 convertible as well as the new purchase of the Ocean Alexander. Need to find original specs on prop size, etc. She is a 43' aft cabin with a single Lehman 120 hp. Current prop(when purchased) is a 28x20 three blade. I have not launched yet so I have no idea of the cruise speed, etc. Any and all info regarding the right propeller would would be appreciated. :

Thanks.