Can I assume that it's a '32 style? If so, TANK'S Inc will sell you a cut to size http://www.tanksinc.com/index.cfm/pa...prod/prd94.htm. The have the OEM size tank as well as a couple of similar larger styles. This is their ~15 gallon size. It's about 1-2 inches deeper then the oem



It's about 6.50 to 6.75 below the mounting flange. Now, if you need a sending unit, that is based on the brand of gauge and sold with the gauge