Sorry, Jack. I know nothing about the black and silver Bilsteins. Are they intended for off-road use? They might be worth a try.
I think if I wanted more rebound control at the rear on a dually with the large unsprung weight of the big heavy axle and four wheels and tires I would look into having a good welder and fabricator build a four shock mount and install two pair of Bilsteins on the rear.
I think if I wanted more rebound control at the rear on a dually with the large unsprung weight of the big heavy axle and four wheels and tires I would look into having a good welder and fabricator build a four shock mount and install two pair of Bilsteins on the rear.