3.6 Johnson GT

[Checkmate2.5]

I found this motor, can anyone tell me about it? It is allegedly a 300gt with over 350hp. I'm not trying to start a merc vs Johnson battle here, so only facts. Oh yeah how fast could this thing move a 21 rally sport?Thanks
http://img.photobucket.com/albums/v694/checkmate414/boat_004.jpg
http://img.photobucket.com/albums/v694/checkmate414/boat_003.jpg

[bigbore]

looks to have a offshore mid to,350hp.?,i'd say in the viscinity of 70-75:cool: