Under bed gas tank options for 1956 pickup

[jds319]

Now that I've got my rear wheels on my '56, it's about to time to find a gas tank to install under the bed. Does anyone know of any junk yard tanks that will fit right in? I know about the aftermarket kits out there, but most of them are only 19 gallon tanks, and I'm afraid that won't get me very far down the road with my thirsty big block.

Any tips or ideas?