RDS Below Deck 55 Gallon Belly Tank Special Order - Ships When Available. Contact customer service for more information on Special Order items. Below Deck 55 Gallon Shape Belly V SG-SU Sending Unit Size 48 X 24 12 34 - 9 12 Side Corners are radius bent, not welded All tanks have 14 NPT pickup, 1 12 fill, and 12 vent fittings Add 3 to height for fittings Gasoline only. No return fitting for diesel fuel Above Deck Tanks have vented caps with guage units Below Deck Tanks have electrical sending uni