I have been driving my 40 ford pickup (45 cab) since the mid 90's. The truck has ran great until recently when tried to run up a 45 degree platform and started running lousy. I think something in the tank got in to the gas (rust?) or something and need to do something. Can you buy a new replacement exact tank for a 45 cab or do I do the bolt and nut cleaning, flush out the line or? Also I can't install a tank in the back of the frame because of the trailer hitch.I do use my truck as a truck so in the bed would limit my hauling. What would you do?