If your boat is currently set up for a single main motor, I think repowering with a single would be the most cost effective way of going about doing it. If money isn't an issue then you could always look at twins, but I think the biggest consideration would be your particular boating/fishing needs. If you constantly go out 40-50+ miles each way offshore and want the extra motor for safety/redundancy... then it's definitely a consideration. If looking at it just to have it, probably not needed imo. If you're looking at a new or newer F350 then they I've heard are quite good, but some of the late 2000's/early 2010's vintages of F350's I've heard can have issues. I believe most of which are the flywheels that would need to be replaced, and I guess some of them were quite heavy, though probably not as heavy as twin outboards. I'd consider looking at Suzuki as well as Mercury for whatever you end up deciding on, new vs used, in that Mercury generally has the lightest outboard options out there, especially if you did go with twins. Or if you wanted to go new, they as well as Suzuki both, make a 350, and I believe Mercury even makes a single 400. A bit more information is needed here in regard to if you're wanting new vs used, your budget, if you don't mind sticking with a single main motor, etc, but yes to answer your question... there's no reason why you couldn't go with a single main F350 on your boat, especially if it's already setup for a single main motor.
