I've got a pair of auxillary tanks I got here on ck5 from nicks72 that I'm gonna be getting rid of due to another change of plans I thought I'd let you guys know about them before I go the ebay route. One is an aluminum copy so it's light and won't rust. The other is the original steel one with the Hickey label still on it and in good shape. I guess they hold about 13gal. each. I have no idea how they mount(I never got that far) With shipping they cost me just a hair under $200. And I need to get that out of them to help keep the wife from killing me for buying other parts. These fit inside above the wheel wells.