I want to remove the fuel tank from the cab of my 62 c-10 and mount one under the bed. I have looked at custom made to order aluminum tanks and also the pre-fab poly tanks sold by Brothers and GMC Paul as replacement tanks for Blazers and Suburbans. Brothers says the tank can be used for 63-66 Chevy truck under bed mounting and GMC Paul sells a similar, if not the same, tank advertised for 60-66 Chevy's. I have been told the width of the frame is the issue in making these pre-fab poly tanks work with my truck. The tank is 26" wide and my frame is about 37" wide. I am considering using the poly tank simply because it is a reproduction GM part and might be easier to work with than a custom aluminum tank (i.e. corrosion resistant, off the shelf parts, no painting required, etc). Has anyone installed one of the poly tanks? What kinds of frame modifications had do be done to box it in. I really need a lot of input on this because I don't where to start if I have to add support to the frame.