Bulldog motor was originally made for the military, they wanted reliable motors and that is what merc gave them with the bull dog. Overkill on the parts for the hp they made, but if you have them they are easy to bump up in hp if you want to.

I think Jaay hit it with #1 below. Remember that motor first came out in a 575hp version with TRS drive.

Thank all for the good info, so as I can see both of them seems to be good engines.
What GPH and MPH should I expect at WOT and the middle range in a PQ 280 Silencer

WOT about 45 GPH.

Cruise speeds 20-30GPH.