If you do not have one, wander over to the MyMopar site and download a factory service manual, free. In fact you might consider downloading say, 69--73. This will give you an insight to the changes every year, and if you ever upgrade to the 73 / later disk brakes, that is all in the 73 manuals, as well.
Somewhere around 70-71, not all cars had the evap controls. As mentioned, for a couple years, there was a separate vapor separator in the trunk. Somwhere around ? 72-73 this was changed to a separator built into the fuel tank. NOTE THAT THIS line coming from tank to the engine bay IS ALSO THE TANK VENT. DO NOT remove/ block/ plug the line unless you make provisions for venting.
One reason I suggested you download the 69 manual is that the 69 tank vent worked well and was VERY simple.
