No. The pictured vent IS the tank vent. Mopar never used vented caps. The 70's / later caps are called "pressure vaccuum" and are not meant for vent. They are only to relieve extreme pressure in the tank
And the line MUST be left open if nothing else is done, as it IS the only (original) vent.
That is, the tank is a completely sealed system
69/ earlier were vented by an open line to the filler neck
70 / later evap emissions equipped were vented through the 1/4 line going up front.
On cars with the line "still present" (and unused) going to the front, you can simply connect a hose down, say, in the wheel well to take care of what little over surge there might be. Some guys have plumbed them into the filter bonnet same as the PCV vent.