The 525 HO kit requires a cam change out along with heads and intake but can run stock exhaust.
The 600 kit has a different rotating assembly and requires the use of headers...I never priced it out either.
The 302 definitely has what I would call a different ride...seems planted heavier in the ass end- due to the twins, its a good feeling.
Our 280's are in reality only 27'-7" long with a notched transom. I havent measured the notch yet, but we are loosing some running surface which gives us less boat in the water and makes it ride like a smaller boat.
I find that the harder I push the boat in 2-3 footers the smoother the ride....not saying stuff doesnt move around in the cuddy though!
I like the feel of his twins planted in the water.

And my buddy has hydraulic steering and I dont....there is a difference in that alone for sure.

verbi69,Once again,been a while since I've been here so sorry for not getting back to you. My 548 makes 640 hp @ 5400pulling ALL accessories(p/s'water pump,wet exhaust,circ. pump,alt)it makes 680 ft lbs tq at 3900. It was dyno at Percision Marine in New Orleans. I just bought a 38' Top Gun with 598s so the 280 is still for sale if you know anyone. Bob

Nice move up Bob. I'm looking at Baja 342's or the Vyper 340's to move up to hopefully soon.
I love my 280 though.