Technical 48 Ford gas tank question

Anybody know what thread pitch/size the vent fitting on a 48 Ford car gas tank is? 1/4 npt goes in about one thread. Looks like some type of compression/flare on the bottom of the fitting. Thanks

 

Read all this helpful fuel fitting info.
https://www.fordbarn.com/forum/showthread.php?t=274257&highlight=gas+tank+fuel+fitting

 

Great info including part #s, The HAMB Rules!

 

That is not the vent, it is the fuel line fitting to the engine.

 

Thanks for the info. Going to be a return line now with a feed line from the top of the tank.

 

As far as I remember it’s a Ford only fitting