Prop help.

I have a 1986 V16o Ray Craft with a 1975 115 HP Johnson. This motor has a 13.3/8x17 prop. Like to get a new one in the future and I'm trying to figure out which one. One salesman said a 13.25x17 4 blade. Run prop check on computer and it said for water sports and heavy loads a 13.25x21 3 blade are a 13x21 4 blade. For cruising and speed a 13.25x23 3 blade are 13.23 4 blade. Like to know What was on this boat when sold new.

Thirty years ago we didn’t have the choices we enjoy today
And today there are professionals who can save you time and money with the correct choice the first time.
Josh at Steve’s prop at fork is such a pro. Get with him a take his advice.

Thanks I'll talk to him.