Gary mueller from jet tech turned a bvm f-16 (the original little one) sized centerline tank into a useable fuel tank that holds 78 oz as I recall. I had one back when and it was awesome. That might be a great way to squeeze some gas into that plane. The tank has a flat-ish crosssection so it would work with low ground clearance as well. I think a bunch of guys used them on converted mavs and such. Plus Gary is a great guy to deal with as well
Dave