I have one of those wonderful in cab fuel tanks in my 73 W100. Its a pretty original truck so would prefer not to relocate the tank. Fortunately, I'm not a smoker as the old worn out cab to tank seal just isn't doing the job. It doesn't look like anybody makes the seal anymore?? Anybody have any ideas on how to safely seal the tank off? Thanks,

 

Actually the tank in cab tanks arnt to bad I had one in my 77 that I had for twenty five years. The big danger was if the truck slid on it's side in a wreck the filler cap would come off. My short box had that and a plastic tank just after the cab under the box. Between the two the truck would hold fifty gallons of fuel. Shorty after the neighbor boys turned sixteen I had the tanks emptied over night, hhmm. Locking case caps took care of that and there safer in a roll over. Try Dodge for the seal you never know!

 

https://www.carid.com/oer/fuel-tank-...9&url=84276877

Is this the one you are looking for?