mustang gas tank?

im istalling a 1966 mustang gas tank in my 55 olds. almost done but went to napa(and looked online) to get a non vented gas cap for a mustang filler neck or a 55 olds filler neck, but cant seem to find one. maybe im overlooking someplace. any advice or part numbers would be appreciated. thanks

 

Here's what I'm doing, I went to the local harley parts guy and bought a used dented sportster tank for $10, after washing it out real good I used my cutoff wheel to remove the filler bung, once its removed you will notice it fits perfectly in the fill pipe of the mustang tank, braise it in there, the sportster tank has a vent pipe that goes from the filler to the bottom of the tank it runs inside the tank and is hooked to a rubber hose and is vented down by the rear tire in the bike.I am just going to copy this design using a piece of 3/16 brake line braized to the filler and drill a hole in the side of the mustang tank for the line to poke thru and braize it there too, this system uses a non vented cap available at any harley shop.

 

Non vented? are you running electronic fuel injection and an EVAP system?

You want a vented cap to allow the pressure to normalize, other wise you will be creating a vacuum in the tank when the fuel pump is trying to pull fuel out.

 

Wow....this is a cool idea...i need to do something with my mustang tank....

 

If the tank filler is in the trunk, it needs to be non-vented with a vent tube routed to the outside somewhere....