77_Tahiti I can't help you much, but I think I vaguely remember a seating arrangement like yours. I have a 18' 1976 Tahiti bubbledeck with a 460 and a Berkley. Not sure but I think it's 330 HP. As for the weight I weighed mine with the trailer and I think it was about 2800 lbs .. it's been awhile, so I'm not sure.
I hope you have as much fun with yours as I've had with mine!