Your new rig comes with the heavier tube axles and I believe it also may have heavier springs, but not sure with the 6,000 lb axles. I would contact Performance Trailer Braking to discuss upgrading to discs. They have the package for the 6,000 axles and installers all over the country that will come to you and install the system. After having our rig upgraded to discs, I will never have another rig without them, regardless of what any salesman says.
https://performancetrailerbraking.com/disc-brakes (405) 626-7009