If you have a 930/09 motor, it is a 1980 euro and is non-lambda. It will be an easy install and does not need any O2 sensor stuff.
If you have a 930/07 motor, it is a 1980 USA engine, and is lambda controlled. You must have the computer for it which resides under the passenger seat. It is needed to control the frequency valve which bleeds off excess fuel pressure in the lower chamber of the fuel distributor. Without the computer, the pressure in the lower chamber will be too high, and your engine will run lean. My engine was worn out prematurely from being run without the frequency valve and computer.
Here is the non-lambda fuel distributor on the left, and lambda style on the right :
If you have the USA motor and the computer, you can leave off the O2 sensor. It will run fine.
Rob
1980SC