I've only had stern drive, currently a 3.0,4.3, and a 5.0. I have been exposed to outboards and jets, I just seem to always go for a stern, which is what Dad always had. I feel the power to cost ratio is Sterndrive. A 300hp 5.7 with drive will cost you about 12k full replacement vs 30k for a Merc 300 outboard.
i think that 30,000 seems a little high for a 300 outboard. you can buy a new 350hp 4strk yamama for under 25,000+ rigging. i have had a few boats in my life time. the current boat i have now has twin yamaha 4strks. they really are great engines. my previous boat had a 2strk mercury. again, anothher great engine. growing up my father had a stern drive with a 350 chevy motor. that was one bad a$$ unit! in my opinion, i will probably stick with the outboard for cost and repair repair reasons. that is my 2 cents.
Keep in mind, outboards are doing exactly what they were designed to do. I/O's are marinized car/truck engines. I've never known of an outboard that was actually worn out (with proper maintenance) as inboards and I/O's often do. A two cycle outboard fed the proper oil/gas mixture would run indefinetly. Don't know about the new 4 strokes though. An outboard also weighs half as much with the same Hp output as an I/O. Less weight, better fuel economy.
Outboards are so easy to maintain. I really love the I/Os I have had over the years, but they have been a pain. 1. 14' Norriscraft - 40HP Evinrude with Electric Shift. (JUNK) 2. 1976 GT150 - 1st motor Merc 650 w/ no power trim. replaced it with a Yamaha 90HP both motors were trouble free. I replaced the Merc mainly for power trim. Got a good trade and deal on the Yam. 3. 1977 CVX18 - removed the original 305 - replaced with a monster 350 'RV' engine - after it ate an outdrive it finally broke after 3 summers of WOT fun. 3RD motor and current motor is a 350 MARINE engine from Zigouras racing 'LOW Compression!' Very nice! 4. 1979 CV23 - Came with a Twin Turbo beefed up 350. Very finicky on fuel quality. Melted down a piston. Engine #2 - Had the turbo engine rebuilt by a local boat mechanic. Nothing but trouble. Engine #3 - I call them Mex Mercs. Paid 2 grand for a 'Brand New' not rebuilt 350 260HP bone stock engine. It is really great so far.
I wish the Outboard had that sound and I wish the I/O had the ease of maintenance and durability. Especially for more HP!
