I am presently rebuilding a flatback, hull is getting csm, 1708, csm, 1708 for a nice firm bottom. Stringers are being placed with 36" inbetween clearance to accommodate 82 gallon fuel cell measuring 35" wide, 44" long and 15" high and will be placed right up to casting platform, c.o.g.should not be compromised with this fuel cell position. Deck will be raised 4", scuppers have been removed and will be placed in transom at deck level. Hope this helps you on deciding tank placement. Just think about your center of gravity, and I believe the gallon capacity will be a huge factor.
