The need to shorten the gas tank for a 4x4 conversion is a real bummer especially with a v10 gasser. You need to start looking for a gas station after about 250 miles. It seems Transferflow is only available on SMB and maybe Quadvan. Has any one used www.aerotanks.com? Thanks, Stosh.
I'm pretty sure you can only use Aerotanks if you have a diesel. Gassers must use tanks that meet a much higher crash standard, and TF actually has crash tested several E-series vans with their tanks installed.
QuadVan does install TF tanks. They can install them on older Quigleys, but I think John said something about the newer Quigley having some sort of interference (crossmember?) with the midship tanks.
QuadVan will also install a 35 or 55 gallon Ford rear tank (55 for extended vans only).