With the trailer hitched to the truck, you are getting all the squat you are going to get in the truck's rear suspension. Measure the height of the ball where it is now with the too-short shank.
Unhitch the trailer and lower it to level, or slightly nose-low, wherever you were towing it with the Armada. Do simple subtraction math to get the difference. Add that difference to the current drop shank length. That is the MINIMUM amount of drop your new shank will need to accommodate.
Example, the tongue sits at 23" off the ground hitched to the Ram now. It sits at 19" when level. The difference is 4". Your current shank has a 6-1/2" drop. Add 4" to that. Your new shank needs to be at least a 10-1/2" drop. More is okay to an extent unless you go stupid like a 24" drop. Then you'll be plowing up pavement.