I think thats the one they call "on the body" weatherstrip and should be part number 4217660 at Dodge. There are no aftermarket seals that I am aware of right now. If this is the part you need you can get it cheaper on the web through some discount Mopar parts dealers.
I found a pretty good match at JC Whitney. It was in their paper catalogue (for whatever reason I have a hard time getting their web site to cough up Dodge parts).
Double check these part numbers before you order to make sure they haven't changed. They are for my '87 RC. The rear hatch is from thier generic rolls of wx stripping. The anti-rattles fit, but they are not of the best quality or fit. The rear curve is all wrong and the a few of the clips are not in the right position so they don't go all the way onto the door tabs. Perhaps someone else knows of a brand that do fit exactly?
Front Door seals: 73PI7610A
Window Channel kit: 81PI0359B
Rear Hatch Seal: 14PI3538P
Belt Weather Strip (anti rattle): 07PI1354T
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