Suggest all around I/O power for Sceptre....

[bobfish21]

1974 23' Tsunami, repowered with 2000 Mercruiser 5.7 LX 260 hp EFI, Alpha gen II.
My cruise is right about there, 25 mph at 3000, never ran her higher other than to make sure I was turning where I should.
Top end falls a bit shy of your 45-50, more like 39-42.
Had the same boat with a single OB when I was young, the I/O hands down way better ride- 1000lbs of iron in your bilge will do that.
In 17 years I've been through 1 set of manifolds/ risers, 1 oil pan, 1 gymbal bearing and 1 starter.
Salt water cooled, boat was in a slip from 2000 to 2006, so no flush after use.bought a 35 Bruno DE, so after that time, little use- maybe 550 hrs total on her.Never had any issues with corrosion, block always contained either water or antifreeze.
Boat is for sale on here.