Your profile....upper right....says it's a da (sundancer)....title of this thread says it's an ac (Aft Cabin)......which is it? Also....does the vessel have CATs?....3116 or 3126......as in your profile?....not much difference in the CATs, but there are some differences.
We have a 98 370AC with 380 gas. I think it's the same hull and deminsions as the 380. Ours is 13 yrs old but has only 220 hrs on it. Great boats but maybe should have been diesels. Ours is a pretty bad performer. We don't have Flow Scans so I don't really know if there is a sweet spot on ours. Maybe it just doesn't have one! The other pieve is the gen set. Ours is the 9.6 Westerbeke. It states 1.3 gallaon per hour, and ours runs at 3600rpm all the time. It seems to me they could have used a unit that has a governor. I had an older Onan on our other Sea Ray which would run at 1800rpm and go up if it needed to. As far as the fuel consuption listed at 1.3 gal per hour is a joke. I would bet ours uses more than twice that amount. Other than those two items we really like the boat. You will find getting exact information about them a little difficult. I have had to call Sea Ray several times to get info. Jason Brennan in Florida customer service has really helped, but even his facts are a little generalized due to their record keeping and drawings.
Also I think someone has started a 370/380 thread so maybe some other folks will step in with their info and thoughts.