Are you talking about the vent window seal or the door seals? Try taping the wing windows around the seal with some duct tape and do a test run. It should help you pin point where the noise is originating from.
I have had problems with the wing window hinge flexing so I don't open the wings anymore.
I remember back in the day both sides of the old man's K20 had folded match books under the wing window latches to keep them from whistling.
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Thanks to Bob and Jeanie and everyone else at Superior Performance for all their great help.
RIP Bob Parks.
1967 Burban (the WMB),1988 S10 Blazer (the Stink10 II),1969 GTO (the Goat), 1970 Javelin, 1952 F2 Ford OHC six 4X4, 29 Model A, 72 Firebird (the DBP Bird). 85 Alfa Romeo
If it breaks I didn't want it in the first place
The WMB repair thread
http://67-72chevytrucks.com/vboard/s...d.php?t=698377