I took the lower heater housing secondary duct (part # 3895932) off my 1968 Camaro 30+ years ago when I ran it as heater delete while drag racing. It is the one that redirects air around the center console. I found what looks like a similar but smaller version of it in the 1968 and 1969 AIM that I assume was the non-console version of the duct. Both AIM diagrams call for the same fasteners # 9427326 but I can't find any info on what they are. AMK shows nothing for them when I run the number.
It looks to be about the size of a #10 screw but I don't know if it uses a floating washer type or a hex washer head type. I don't want to damage this part or have it come loose using the wrong fasteners on it. Any help would be appreciated.