I have a Volvo penta SX outdrive behind a 5.0. I had done some research and everybody said that it would make a big difference from out of the hole and mid range from my three bladed prop. I installed it and honestly I did not notice any difference except for maybe it was a little smoother on top end so I'm just giving my honest results. Very nice looking prop I think these guys have a great product it just didn't seem to work for me thank you