Removing that fitting might not affect fueling, but it will probably stall the car when being driven. Your Pantera uses a vented cap on the filler spout, but a breather as well was deemed necessary by the designers- like on hot days. What you CAN do is drill out the 3 pop-rivits that hold the little dome-fitting in, then tap the rivit-holes & replace the stock dome with an anti-rollover or anti-spill valve from Hall or other vendors. The anti-rollover valve uses a smaller ID hose than stock, so you'll need one of these, too. The whole deal runs less than $50 and is good insurance. The vent hose should go either to a (new) charcoal cannister or to the air cleaner base so fumes are burnt up, not vented to the atmosphere.
