I have looked at the old posts and I cannot figure out what is differences on the trim upper and lower windshield. I have the pillar pieces but need the upper and lower molding. When I look at the 64-7 they look the same

 

The upper and lower moldings have a side profile like at "T" where the horizontal part of the "T" is what you see after installation. The vertical leg of the "T" sticks into the car between the windshield gasket and the body. This leg is longer on 63 trim and subsequently uses a different clip. https://www.corvettecentral.com/63-c...-pieces-332331
The shorter leg on 64-67 Convertible trim uses a different clip like this. https://www.corvettecentral.com/64-6...-2-sets-332312
The trim and clips for a 63 are not interchangeable with 64-67. You can use 64-67 convertible lower trim on a 63 coupe if you use the appropriate clip. I've done this a few times since you can get the 64-67 trim for about 20% of a 63.
I think the 64-67 coupe upper trim has a different profile than the 63, so would not work in matting up with the vertical trim.

 

All 63 window trim is one year only .

 

63 cp or convertible lower trim are the same. 63 cp upper is 63 cp only. There is a reproduction upper but it is junk.

 

Are you refuting to the lower windshield trim ?

 

Not really window trim, but also those forward edge door stainless moldings are SWC only. Those pieces have never been easy to find.