[Tom Wells]

DD,

Here's an older reference to the Cobra bung question: First Coast Cobra Club • View topic - Header & Collector O2 sensor bung locations

Both locations seem to work fine for tuning the EFI with the wide or narrow band sensors. The wideband sensors are greatly preferred.

Here's another set of photos of the Zephyr's bungs: First Coast Cobra Club • View topic - Zephyr October update (last one this month I promise LOL)

They work great for carb tuning using the LM-1 or 2.

Hope this helps,

Tom