Your blower has normal wear

If the wear is down in the troughs/side of the rotors then its done for. Heat is the biggest enemy of the SC. Not just for the IATs, but for the blower itself. The wear you see is from the rotors expanding slightly due to excess heat. Since the tightest clearances are from the tips of the rotors to the case, they expand slightly and wear down. This is normal, along with some teflon wearing off the tips/troughs. When the SC gets too much heat, the rotors expand even more and contact each other causing the tips to dig into the trough. The final stage of expansion causes the sides of the rotors to contact putting even more heat into the mix via friction, often right before the unit locks up

Belt slip is a possible problem, but easy to spot. Look for black dust accumulating near the SC pulley. Dont see any? Then you're not slipping

IMHO, Id leave the blower alone and upgrade the cam. The LS9 is a good budget stick, but far from a good aftermarket blower cam
Also, You'll want a really good intercooler pump. Those three heater cores you're using for heat exchangers do the job, but the pump has to work extra hard against all that
Finally, watch your intake elbows during a dyno pull or something (mount a camera under the hood and do a few runs if you have to). If the big elbows start to collapse at all, then your filter is too small. Compressors (SC/turbo) are extremely sensitive to restricted inlets. Basically, if the air isnt there, it cant compress it. A collapsing elbow would indicate a vacuum in the intake tract. Pop the filter off and do a test run to verify, the boost gauge should go up