020-01-11735 $95.42. 30, 74, 75, 98 gallon tanks. Gas. 020-01-11736 $88.33. 50 gallon tank. Diesel. 020-01-11737 $137.12. 50 gallon tank. Gas. 020-01-11738 $132.15
http://www.transferflow.com/additional_products.html

Diesel. 020-01-11735 $95.42. 30 & 98 gallon tanks. Gas. 020-01-11736 $88.33. 50 gallon tank. Diesel. 020-01-11737 $137.12. 50 gallon tank. Gas. 020-01-11738 $132.15
http://www.transferflow.com/crossthebedtanks_0.html

020-01-11738: Auxiliary Tank Fillneck Kit for 50 Gallon Gas Fuel Tanks 10.0 lbs $132.15 $132.15
http://www.bondequipment.com/servlet/Cart?category=Auxiliary+Tanks%3AAdapters%2C+Kits+and+Tools&no=168&product_no=168&searchpath=1170830&smode=add