Rear Blazer window won't fully go up

[Ski-me]

89' K5.

I replaced the tailgate with a new(er) one that had no rust in it. Replaced the lower channel that supports the window (glued in with silicone). Put everything back together and works like a charm!

However, the window doesn't go all the way up into the felt channel in fiberglass top. It touches it but doesn't fully go within the channel.

The felt is the original one and I'm wondering if it is somehow squeezing the glass to tightly to prevent it going all the way up?!?

It looks closed from the outside, visually. But if I go through a car wash, water comes in pretty good at the top of the glass.

I'm wondering if I shave off a little of the felt on the inside, it would allow the window to go the rest of the way up....looking for ideas.

Thanks!

[mickeykreg]

Mine was doing this after swapping my rusty tailgate out for a clean one off of an 87. Turns out the outer shell of sheet metal was pushed in, right in the center, just far enough for the window roller frame (that the window is siliconed into) to catch on the outer felt, which was preventing it from going all the way up. By standing off to the side I could see the concavity in the sheet metal alignment. (hope this makes sense)
I guess after all the years of slamming the tailgate the sheet metal gives just enough for this to happen. I pulled it back out enough to work, and shut it from the edges now, instead of the pushing in the center, but I still haven't found a better fix.