Sounds like the same set up I used to sell. I was dealer for TSM. Sounds like rotor warped. Not sure what they use now but the last 2 kits I saved for personal use has FORD rotors machined for 8 3/4 Dana 60 fit.
Warped rotors will cause a pulsation. (50 years in the business) Rusty is correct, these rotors need to be turned (fine feed rate on the rotor lathe) and a non directional finish added.