+6 and Nittos is going to be a challenge as that is a true 37. Not sure which BFG you were on but my load C are great, no balancing issues, wobbles etc. I did do RPG collars up front and dont notice any difference in how the truck handles or accelerates. Those Nittos I think are at least 10 lbs more which is a huge amount at the wheel/tire level. Delf would hurt performance and MPG.
I love the Goodyears. They are great tires and might be my next one once the BFGs go. Think They are pretty light in 37s too.
Glad you ended up back in a good place for you-great tires and great truck.