The Herbie-X tank has 16 gallons, and was custom made by Fuel Safe. They could make another one now that they have one made.
It also has a kevlar bladder inside. Get your wallet out $$$
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1970 T1 W/MassIVe 2913cc RAT/?EFI? w/direct fire (very soon) and 915 trans
1962 SC 1776cc SP 944NA brakes, 993 wheels
VKG