Taking a page from "The Incredible Hull" website, I built some cardboard mock ups of the new fuel tanks for measuring.

Based on my calculations, the 2 tanks should be about 35 and 30 gallons.  65 total from the old 80 gallon space.
But it will also have a nice bilge pump location.  Now to send away the measurements and get a quote.
If anybody wants my measurements, let me know