There is no reason why you can't drop in the 5.7. As mentioned, the v6 uses a different gear set. You may be able to "prop" yourself into a fairly comfortable RPM range by going up in pitch. It's been done lots of times. Now, you would certainly be better off if you had the matching drive gears...
The 5.0 is a Chevy small block. It is one of the most common V8 engines ever produced. Your options are sort of limited to the same type engine.
You can go up in size with a 5.7L (350) in the exact same footprint. That is, more or less, the identical block with taller deck.
Usually you can find...
You'll probably find that the speed-per-dollar return is REALLY small. That is, of course, if you change nothing else but the engine's output. In order to get significant gains in speed (I assume this is the goal) you'll need to look at everything...starting with the propeller, then the cargo...
Loved my old Anacapri. I had to send it to the landfill but it was nice while it lasted. If I still had it, I would cram a BBC in there with a Bravo 3. It would absolutely rip.
I'll add an oil change before you put it up and another when you recommission. Oil is the absolute cheapest insurance you can buy for your marine engine. I run straight SAE 30.
Absolutely do not run this engine until you have diagnosed the problem. Running with water in the oil will quickly remove the babbitt layer from your bearing shells. Let's hope it has not already happened. You must must must change that oil several times if you detect water. That is, change the...
You will probably not see any seat-of-the-pants improvement with a 4 blade over a 3 blade. The best thing you can do is employ the services of a propeller shop. They can assist with prop selection and you will be able to try several before you decide.
The thing that makes the boat spacious on...
You have a fairly heavy boat that is on the verge of needing twin engines, You already have a not very pitchy prop at 17. Going to a 19 or 21 will really make hole shots a real drag. On top of that the 5.0 isn't a particularly stellar performer. I don't think you can "prop" yourself out of this...
I would never live in such climate, but gas won't go bad sitting that long. Seems like you do your "cruising" on frozen waters and are regularly buying fuel for your other gear so I don't think you're really at risk in that sense.
A few months of sitting during winter will not hurt the gas. You can put Stabil in there but it's not necessary. It's always good practice to do an oil change before you put it up for winter and then again when you commission in spring. Oil is the absolute cheapest insurance you can buy.
This is nightmare fuel for sure, at least for me. I'd be pulling out ALL that funky wiring and installing new harnesses. I don't want any fires or other surprises on my boating excursions! To the OP: boats are like aircraft in that once you leave the safety of the dock, you're at the mercy of...
Weber carbs are just plain different. They need lots of love and if they don't get it they go on strike. That said, most carb problems are in the distributor. Be sure that you have all good everything...cap rotor wires plugs timing...before throwing hate at the fueling.