I was scratching my head when I originally saw the pic, me said to me....
hey wait i'm looking at the fuel pump, harmonic balancer, and what looks like the timing chain assy, but hmm the headers are also facing back. I mean Front, No wait, ok im confused, LOL...
So the back of the motor is right behind your drivers seat and the front of the motor faces the back of the boat and the headers are facing the front, I mean back (which is actually the front, LOL)
Man that must have taking some thinking and modifications, THAT'S THINKING OUTSIDE THE BOX

Old School 426 Hemi Engine ? Is it Jet Drive ?