I am trying to figure what belt is the best belt and size for a 4.9 with A/C and smog pump. Currently I have a gatorback 4061000 and it seems to be to big. This is my second belt and it is causing my alternator to squeal. Any help would be appreciated.

 

Why don't you try the next size down?.

 

Is your automatic tensioner max-ing out? Or perhaps the spring in the tensioner is worn?

 

The tensioner is brand new, thought it might be bad so I replaced it already. and yes, it doesn't start out that way but I guess the belt stretches that much then the tensioner is maxed out.