150? I'm thinking 40 per engine and 20 per drive.
And you'd want more power than 480s.
I think you'd be closer to $250 by the time you're done.
Many here come up w/ an original number, and usually end up sometimes double that guesstimate.

Now that would make for an interesting thread in the GD.
Estimates vs Acutal to get'r done. :)

hmm you might be right, but I would use Italian Top System surface drives instead of Arneson, good quality and have also a low planning speed which is important for the big seas in the Maltese waters, I would calcuate it would do 40 plus with 480s, not the speed some of the Powerboat lovers love over here but I am good with it
I prefare a good strong all sea boat, and in the end the Magnum hull is made for max 50-60 knots after that you will have a lot of drag due to the forward deep section which has about 40 50 degrees to my knowledge

what happened for this project
would be nice to see what have been done for this 38

Magnum 35
 

I purchased a '75 MAGNUM 35 in '95 , in upstate N.Y.,talked w/ Everett Sutton. MAGNUM G.M. at the time, last 35 built!! Boat had twin 400 H.P. Cyclone's, best speed was 39.7 GPS, boat would run in any sea condition, cruised at 28-30 burning 35gph. Sold it in 2000, for another 27' SEDAN w/ 300 h.p. o/b. 35' HIN 351550874........."HIGH LIFE"

Magnum 35
 

Forgot to add that after a couple of years I called MAGNUM and talked with their engineer about installing diesels. App. cost to replace V-drives and running gear would be $68,000, for a boat that a payed $32,000 for !!! Can buy alot of gas for $36K. HIGH LIFE

The tab on the 43' Cary is at 45k and climbing...:lolhit: Big boats aren't CHEAP..:daz: