Read these threads, it shows the differences in manufacturers seals and gives part numbers of the ones that fit best. I had bought Precision seals and didn't even open them. Bought the seals recommended in the thread and they worked great.
Gary
http://67-72chevytrucks.com/vboard/s...d.php?t=660294
https://67-72chevytrucks.com/vboard/...t+window+seals