New 63 dart windshield gasket?

No, I have not heard of GoodMark, but I am guessing that if RockAuto is selling their products, they can't be all that bad. $35 is a great price. I imagine you'll still need to get a locking strip too.
I bought my windshield gasket and locking strip from SteeleRubber and the rear window gasket and locking strip from MuscleRoad. They were quite a bit more than $35.