I have the LC-1 with a digital gauge and have used it to tune my Edelbrock carburetor. With the Edelbrock you can swap out the springs and jets fairly quickly, and monitor the AFR to see the effect.
For example, when I feel the infamous Edelbrock part-throttle bog (which means you need a different step-up spring), I can also see the AFR go very lean (bog) and then suddenly rise and go to a normal AFR.
A couple of key points on the LC-1:
- The Bosch O2 sensor needs to be mounted as close to vertical as possible in the exhaust pipe to avoid water damage from condensation. The sensor is heated, so it can be mounted almost anywhere before the catalytic converter and still function properly.
- All ground wires in the LC-1 should connect to a common ground, and then you should have a wire from that ground point to the engine block. This ensures you get good AFR readings.