Strange Noise

I have a 95 4.3 5 speed with a fresh 4.3. For quite a while now I have had this noise from my transmission that sounds like chatter. It is only when I accelerate. In third my transmission hesitates some. I have not had any other problems, and other that third my performance is not affected. Is this normal, or does someone have an idea as to what it is.

Sounds like the clutch is not aligned correctly.