As I satated you need to get your front axle to original height/weight. I showed you an example of this with my weight tickets from the cat scale..
I said its do able, but you need to set up the WD hitch better.. We gave you all the knowledge here already to do this..
Does your truck have a trans temp gauge built into the dash info center?
When I towed with the factory trans cooler that is part of the radiator my trans ran very very hot.. I immeadiatly changed the fluid, filter, and got a gauge to determine temp,,
I then installed the biggest trans cooler I could fit behind the grill.. My temps never exceed 190F now..
My trans was the weakest link in towing the weight I am... My spring pack on my truck is the weakest link for TW...
My truck came with LT tires rated at 2270 lbs each @ 50 psi.. LOL.. So tires are not the weakest link..
All trucks have a weak link..
Follow the advice given and set up the WD as shown.. Then get to a scale as I show..
If you can restore the front, which you can, you will be fine...
You never told us the spring bar ratings?????? IMO you need 1000 lb ers.. If they gave you anything less return them and tell them you want the 1000 lb rated ones...