Windshield and rear back glass on 67 barracuda fastback installation

The OEM screws were special. They had a #8 shank with a undersize #6 head so the trim can fit in the clip with the screw head. Drill charts show 1/8 or 5/64 for #8 screw depending on material and thickness. Try 1/8 in a similar sheet metal. If aftermarket is providing #6 screws you'll have to back to the charts online.