Just rememberd this after i posted on another thread. I was out on our boat a few weeks ago and i got talking to the shop tech about our boat. I asked him if anything special was done to the engine in the boat to make it fine for running at 5000rpm for 90% of it's life. He said that the engine was basicly the same as in the trucks and the 6 litre LY-6 from GM which puts out over 400hp whats in our boat, got over 1000 hrs of testing at 6k rpm.

This then got me thinking about all the people that say it's not good for the 5.4 to rev for long periods of time when going up a hill or pulling a trailer. It seems that these size engine have no problem with it at all. Our boat gets maybe 4-5 hrs a day at around 5k rpm and it's fine so their should be no issue with the 5.4 doing the same thing.

Our does anyone know why a boat can do it and a truck cant?