Truck has always done this, even with OE clutch, now with SB OFE clutch for 50k miles. Just that growling/rattling niose when you let out the cluch at idle in 1-3rd gear.
Never thought much of it. Did it even after clutch replacement w/ new throwout bearing.
BUT, I read on an unrelated thread here recently that someone replaced their harmonic balancer to take away that noise.
Now I think it's getting worse (probably not, but I read the harmonic balancer part and know if the HB splits apart, it's not good for the bottom end of any engine).
Anyone familier with this issue or confirm replacing the harmonic balancer helps/eliminates the noise?

 

You mention the vibration is getting worse. Check your stock damper. If the stock damper is intact, hasn't spun and the rubber is good I'm thinking there is another issue. The fluid dampers do mask a lot of vibrations but I would look for the cause of the vibration. I changed out my factory damper even though it looked good to a fluidampr and the vibrations reduced considerably. I still think I have an underlying issue that the damper is masking. (beings that I just lost an injector)