I spoke with Four Winns today, and things moved quickly.

The space allocated on the 278 for the AC unit has incredibly tight tolerances. In fact the back of the unit actually touches the hull in some fashion. Consequently, upgrading to 7K or 10K unit is out of the question as there has to be enough room all the way around. Aside from that, it would be a huge undertaking to help one customer. Many times I've though to myself, "Surely I'm not the only 278 owner that is having this problem."

A short while after speaking with FW, I get another call back. They spoke with Dometic and came up with a solution. Dometic/Cruisair has a new model of AC out called the Turbo Series. It's not actually for sale yet, only available to OEMs. Dometic offered this unit to FW who agreed to pay to have it installed for me. This also includes relocation of at least one duct. The new unit is 6K BTU but also has a much higher airflow volume and some other benefits like lower power consumption and most importantly a smaller footprint, i.e. the unit will FIT in the existing space without re-engineering the boat.

There are still some details to work out, such as the fact the units are on backorder but I was told they were going to make one for me. Also, scheduling of the AC tech. The expert in the area travels all over the southeast and is about 6 weeks out.

I'm confident we'll get the issues worked out and cautiously optimistic this will help my situation. This is great news and I give both Four Winns and Dometic a big thumbs up for their willingness to do this.

I'll continue to provide updates as I get them.

These ar the only links I could find regarding what I believe to be the new units:
http://news.thomasnet.com/fullstory/509188
http://www.cruisair-southeast.com/