That's simple enough to answer your truck engine isn't designed to run high rpms.........racing and outboard engines are.........If you ran a pickup engine at the operating rpm's of the aforementioned platforms you'd over heat it real quick........

That's a big big boat, you guys are getting a little worked up about speed. It won't be that fast.
It will be fast for a Giant boat, but not by fast bassboat standards.

Hang that beast on a stroker and then I might get worried.

You are also comparing horizontal to vertical engines. However I am not a fan of forced induction for reliability. I do wonder what kind of boost is maintained at 6grand.

Just so I'm clear as to the absurdity of this argument.... You're saying that when you're running your motor at 3/4 throttle you are riding around accepting the fact that you are damaging it? Have you heard of friction and heat? Let me go grab my owners manual for my Yammy 300 and look for that paragraph because fishing trips with me are about to get a lot more scary.

Use common sense here..... There's absolutely nothing wrong with operating your motor within its designed operating range at let's say, 3/4 throttle.

Here is a head scratcher 6k rpms really isn't max throttle tho.....

I realize your position is getting harder to defend. On my Merc 2.5 with an upgraded A6 ECU we wrote my fuel curve where it didn't dump fuel until 10 K. And while that's fun racing people across the lake it keeps the motor too lean around 4 K where many of us operate running from hole to hole on a typical day of fishing. I also increased the stock porting and increased the fuel pressure from 30 to 60 psi. so the motor was still within it's range at 9K revolutions.

All of this doesn't change the fact that operating your motor within it's designed RPM range does not "harm" the motor if it's less than full throttle. Come out to the drag races sometime and talk with the guys that build these race motors for a living. We were just in Mount Pleasant and headed to Marble Falls in a couple of weeks and ask those questions you have about operating at less than WOT. You aren't doing the damage that you think you are.

I used to build engines for race cars all the way up to pro mod dragster. An old hand I used to work with once said every short block has a certain amount of revolutions it can turn before something fails (obviously catastrophic events aside such as detonation etc). The more RPM you turn the faster you get to that failure point. Sure lugging a boat around puts alot of drag on it but cruising at 4800 trimmed up nicely is going to give the internals a longer life imo

No mystery that once you can feed an engine past the magic 7k rpm you're lighting the fuse on that short block.