Here's the problem;
The belt usually lasts about a hundred miles before it shreds and has to be replaced or comes off entirely.
Background, (second hand information on work performed);
1982 Jamboree, 258 six cylinder carburated engine catches fire. Carburation replaced with MoPar fuel injection.
It appears to be a quality job other than the belt continuously coming off.
In the attached pictures it shows how its getting shredded. The belt is walking backwards on the harmonic balancer to a point where it almost comes off but it never makes it that far because it shreds first.

I thought I had this problem solved when I changed the 6 rib belt for a 5 rib belt. As you can see the 5 rib belt is coming off too.
This is what it looks like with a new belt on. When the engine is revved up you can see the belt on the water pump walk back towards the engine. You could also see this happen when the 6 rib belt was on.
I guess what I'm mostly thinking is, when this type of swap is done is the harmonic balancer or any of the other pulleys replaced? If so, can one of them have been replaced with the wrong one?
Anybody ever have this problem or am I the only one? <img src="/forums/images/graemlins/confused.gif" alt="" />
Thanks for any help.
Gary