I am thinking of using the upstream O2 sensor for for my downstream location due to the added length provided by the upstream part. My headers have the O2 location further out.

The upstream sensor has a length of 18.9mm. The downstream sensor has a length of 13.4mm.

Besides these differences, are the plugs the same?

Are the output voltages the same?

https://www.autozone.com/engine-management/oxygen-sensor/p/bosch-oxygen-sensor-16274/313004_0_0?searchText=O2+sensor

https://www.autozone.com/engine-management/oxygen-sensor/p/bosch-oxygen-sensor-16276/313005_0_0?searchText=O2+sensor

 

To update, I did purchase and install the Upstream O2 sensor in the downstream location with the longer wiring harness. It's actually in inches not millimeters. So it does give significant length to be able to compensate for the aftermarket exhaust. I've only ran it for about 30 miles on the highway and city but so far no codes and everything seems to be working out pretty well. It seems like a good alternative to the vrp O2 sensor cable extension that sells for just as much as an O2 sensor.

and I'm curious to see if other models O2 sensors have an even longer wire harness if required other long tube headers.