What is this?

In '73 the OSAC valve was in the firewall. In '74 it moved to the aircleaner.

In '73 the OSAC valve was in the firewall. In '74 it moved to the aircleaner.

In '73 the OSAC valve was in the firewall. In '74 it moved to the aircleaner.

In '73 the OSAC valve was in the firewall. In '74 it moved to the aircleaner.

In '74 and later the OSAC was on the air cleaner, but in '73...you guessed it...in the firewall.

:D