Seat Belt Problem!
Is this a restoration or is the car modified ?
If it's modified , then why not just replace the stupid things ? I've got a set of Mark XV 3-point belts in my driver Coronet , and I love 'em !
I've long despised Chrysler's 1972 & later seat belts (the 1970-1971 two-piece arrangement is the best factory setup in my opinion) , as they're uncomfortable at a minimum , and downright dangerous at worst (especially the '72 and '73 models !).
The 1974 & up "Uni-Belt" is okay when it works (!!) . They were notorious for hanging-up pretty early on . When I was a kid , my friend's parents had a '75 Dart 4 door ; and by 1976 , the seat belts were already a pain in the *** to put on (so much so that my friend's parents didn't even bother wearing the damned things , but we kids we "no excuses" supposed to put 'em on).
While I'm on my soapbox ; I also despise lap belt only seat belts . I'd rather parish in a car wreck than be paralysed because the lap belts hyperextended my back during impact . This very thing happened to one of my cousins !
So , yeah , either remove the bastards and clean their mechanism , or replace 'em with some upgraded pieces from Mark XV or whomever .