Repowering a AMT 4" trash pump with a new B&S 305447-0037-G1.  This new engine has an oil filter, and on top of the filter it looks like a sensor with a tab for an electrical connection.  This is a bare tab, no wire attached.  Is this part of a low oil shutoff system?  If so, what kind of wiring would be required to make it work?

Sounds like a low oil cutoff switch.  
 
You just have to run a wire to the tab and then to the ignition coil ground connector.
(when you turn the key off it kills the engine, same circuit)
 
When the sensor detects low oil, it kills spark (actually most of the spark), enough
to turn off the engine.
 
.