10" or 11" brakes?

Depends on what you do in the front. If you stay with the 10.87” disks in the front then the 10x2.5” drums in the back will be fine. You can run the 11x2.5” drums, but you’d probably need to use 7/8” wheel cylinders to keep the brake bias right. So at that point you’re just adding a bunch of weight for not much improvement in actually stopping.

But, if you use the 11.75” disks up front the 11x2.5” drums out back are a great addition. And if you’re planning any corner carving the larger fronts will help a lot. Some of it of course depends on your tires. I ran 11.75” disks and 11x2.5” drums on my Challenger for the entire time I was driving it, so 70k miles. They worked great. And I ran the same combination on my Duster for awhile too before I went to DoctorDiff’s 13” disk kit. And I ran those with the 11x2.5’s for quite awhile, they worked well.