in my car, i put the sensors right after the collectors. mine are more at 3 o'clock cause i wouldn't be able to install the sensor if it were higher. first time around i really cheaped out and put in narrow band system, money was tight at the time, but it does tell me if i'm running rich, lean or optimal. i figure with the bungs installed, i can always upgrade.

what gas are you using with your O2 sensors? anyone run leaded fuel with these?