EEC v. non-EEC fuel tank

[SWCEXPAT]

Hey Guys, have a '72 F350 and I can't figure out if my inside the cab fuel tank is an EEC or non-EEC type. When I bought the truck a few years back it had an aftermarket locking gas cap on it. There are many times (especially after I top off the tank) that I leak a decent amount of fuel through the gas cap. So, would that imply that the tank is vented through the cap gap? And no, the gas filler pipe is not an automatic shut off type-which can be frustrating, lots of overfill! Is this normal or is this something that needs correcting? Thanks

[ok68crewcab]

Not sure about a 72 but my 68 is vented through the cap. I also park it on an side ways incline and I try not to fill over 3/4 full as it will leak a lot if it is totally full.

[idaho_cowboy]

Likely vents through the cap. Might need a new cap...

If there's no extra hoses on top the fuel tank (besides the pick-up tube) then it's through the cap.

- Joseph

[SeapineF37]

my 72 f350 vents through the cap. from what i know thats most common on all f250 and f350 trucks and all but the later f100 trucks. cab tank is about 19gal and if i fill it to the top it leaks at the slightest angle when parked. planning on changing to a side frame tank because mine is a flatbed but for now i play the drive til 1/3 tank fill to 2/3 tank game whch is like $20 per fill-up. anyway, fairly certain its a common issue.