So my slave cylinder went out on my 06 3500 and a bought a master/slave cylinder all together and when I installed it the clutch is very hard and when I push it to the floor it makes like a grinding noise. Any suggestions on what to do?

 

It sounds like its time for a new Throw Out Bearing. It is a fairly cheap part (<$50). Unfortunately, the tranny has to come out to change it. While you are in there, you should replace the Pilot Bearing (<$10) and the Clutch (more $$$).
Back to morning brew . . .