K so got a stock 454 mag with a 24p 4 blade prop. Well top end is great. But with more the 3 ppl I'm wot for like 10 to 15 sec to even half ass plain. What prop would help me. O its a strep hall boat that tops at 67 with that prop.

Exactly what prop????
What rpms are you spinning it???
Is that a GPS speed or off a water speedo???

One thing to keep in mind is that the 280 needs to have the trim tabs put all the way down for putting the boat on plane.
These are big boats for a sinle engine.
My 280 had 575hp in it and it got on plane a heck of alot better than when I had the stock 496 HO with 425 hp.

With 4 adults an 2 kids prop 725 lbs of ppl 3/4 tank of fuel i was wot a good 10 to 15 seconds go get up on plain. Doesnt that seem exstreem

keep your cooler and luggage up front. if you are using the back seat cooler and everyone is sitting in a seat, it is gonna be a bit sluggish til the front rolls over. have someone move to the front from the back seat, it will help. i am probably about 500hp and turning a 28p. i am ok until i get over 6 people then it works a bit to get on plane.

What is the best way to get hp from a 454 mag?

I have a 1995 powerquest spectra 22 foot with a 454 mag. and am running a rev4 21 pitch. Just bumping the rev limiter at wide open throttle. I think you have too much pitch. My rev limiter is 5000 rpm. Do a search on 454 mag here you will see lots of info on upgrade packages. Or you can try Tyler Crockett I believe he sells a package for your motor

Maybe a 5 blade prop might be something to think about...

Are you using the trim tabs?
Drive tucked all the way down?

You may consider my labbed 24P Maximus in the swap section?