I don't know if this helps but my dad hatted the gas tank coming from the center of his 46 Chevy panel truck (really small tank) so we removed it and placed a tank under the rear of the truck with a small goose neck coming up flush to the outside of the truck. We used a Polyethylene Gas Tank out of a 53 Chevy car including the fill nozzle. It even came with the straps! thumbs_up

Jason

Here's were we bought it
http://www.nationalchevyassoc.com/shop-online/product/1117.html