The 67 L35 had a change toward the end of the model year. If you look in the AIM (UPC L35, sheet A8, item number 1 - Air Cleaner asm), it shows P/N 6483656. However, note 2 shows "was 6424434" on April 6. 1967. The 6483656 utilized a chrome lid (P/N 6421832), but the superceeded 6424434 used a black lid (P/N 6422356). The exact change over date is unknown.
The 67 Camaro with 302 or 396/375, the 68 Camaro with 302 or 396, and the 69 Camaro with 302 or 396 (exc ducted hood) used the 6423907 assembly, and all these have the chrome lid.
My car is a Los Angeles car and the instructions are straight.