I have a like new Acme 541 that I got from Nettle Props and used on our 86 Sunsport. It transformed the boat's performance and I said back in an old post here that it would be the first modification I would recommend to someone who is using one of these boats for surfing. It got rid of the cavitation, got the boat up and going much quicker and cleaned up the surf wake. It might have added 50 rpm when at cruising speeds but that was hard to pinpoint. It was a great upgrade.
I am selling it as we got a new boat.
$300 shipped to you in the continental US, in it's original box.
Thanks
Kevin