You are right. I had already decoded the cowl tag : 3L from the cowl tag is RPO Z22 and 4N is RPO L35.
Complete Cowl Tag:
04A A549
67-12437 LOS-29496 BODY
717-Z C-C Paint
W2MG3L
4N
I decode a 67 Camaro Coupe, std interior, made in Van Nuys, Blue interior with bucket seats no headrests, Color Ermine White, No Vinyl Top,Windshield only tinted, TH 400 since made in Van Nuys, center console, RS package, SS package w/ 396/325hp. My other question is how many like this were made? My guess is about 300.