Reply to neil:
Chris, your gauge might be non-original, since the dipsticks have the fuel quantity engraved on them. If you can find someone to lend you theirs, you can get one made up with the quantities correctly scribed.
Cheers,
Neil
(26 gal on mine too)
ozcat,
Here are all the capacities from the original manual that came with my 1956 D2
All U.S. measures
Cooling System -------- 7 1/2 gallons
Crankcase, lubricating oil ------ 3 1/2 gallons
Transmission, lubricating oil ------ 2 gallons
Final Drive, lubricating oil, each side ------ 1 gallon
Fuel Tank ------- 26 gallons
Hope this helps............ Bill