Forgot to answer this, tensioner on the 3.5 has marks as do most others, indicating the stretch or wear limit on the serp belt. Kind of a moot point though as most belts have so much kevlar etc that they just fracture and break before they stretch any real amount.
Hard to see in the pic below but on the tensioner arm there are reference marks, B & C, that are the wear limit against the mark @ A.
This pic is after I installed a new belt trying to kill the squeal.
Check post 28 before you order.Thanks, so I am going to guess these are universal. So the link I posted for Advanced Auto Parts. Is the correct one ? I hope this finally fixes it. I already had it replaced once at the dealership (under warranty)and it came back 30k later (out of warranty). Dealer said they would not pay to fix it again. Ordering the part and will use Midas to fix it. Thanks for all your help !