So with no downgrade for the lift you're at 8750? I assume that is max. towing weight correct? If so that's about 250# more than my old 1500 Chevy and sounds about right. The 3.92 gears are good, but offset by the big tires. Aside from weight (be VERY skeptical of the mfr. listed weights, they are usually for a totally stripped trailer) I would be concerned about the hitch; with a truck that tall the drop to get your ball low enough will put a tremendous amount of stress on the receiver, suggest you have a reputable hitch shop take a look, you may even want to flip the trailer axles to get the ball up higher.
I would still recommend a shorter trailer regardless, those tall tires will also be an issue as they will flex much more than regular tires and may contribute to instability. Make sure the weight is accurate, not generic, for the specific trailer as delivered, then carefully decide what you're going to put in it. You'd be amazed at how heavy all the food, clothes, pots/pans, etc. is.