I had the same thing happen on mine (86 C20 w454), I was getting the fine rubber shavings also and the squeaking noise was driving me crazy I changed the tensioner pulley and it still squeaked, What I finally did was change the belt to a 1" smaller belt and it went away completely ! no more squeaking or rubber shavings ?? I don't know why BUT its been over 7 months and I drive it everyday and still no problems.

I also installed a serpentine set up on my 51 and ran the smaller belt... so far no problems

Its worth a try

Good luck bro.
Todd


Some people are like Slinkies, Their not really good for nothing... But they still bring a smile to your face when you push them down the stairs.

1951 3100 350 TBI Gallery Toddzilla... "$old"