18' with Merc 115 (1988 Both of them) Best Prop?

[McGillicuddy]

I have no problem with them. I took one an alum Vortex I think off my I-6 merc 115 because it was way too much pitch for my Seafari. I went to a 17 p black max and it was still too much pitch. A 13.75x15 black max is perfect for my rig. I get 36mph @ 5500 rpm and 2.1 mpg while cruise gets 2.4mpg at 4000 rpm for 24mph.

I would, however, suggest you try a Merc Black Max or Quicksilver Black Diamond in a 13.25 dia. x 17p. you might even get away with a 19p. My prop guy loaned me 3 props (2 of them stainless) and said bring me back some good notes - didn't even ask for a credit card. I would see if you can borrow a black max/diamond (everybody has a few of these in their shop).

BTW I got 2 new black maxes on ebay for $50 each so look around. Both had flo-torq II hubs included, also...