Ive got a 13.75 by 15 aluminum prop on my 2010 merc 50 horse bigfoot. Its on a lowe roughneck 170rv. It performs well out of the hole and top speed is 30mph. It sounds like the rpms are high at top speed but i dont have a tach. I want to switch to a stainless prop and keep the same performance, what size and pitch do i need on the stainless prop?
