Chevrolet Repair: oil pressure sensor

Question
Where is the oil pressure sensor on a 2007 Chevy Silverado . It is a 4.8 L V 8 1500. The reason I ask is my oil pressure gauge is at 80 which it should be at at least 40/43.  But when you are driving down the road it moves down to zero then the it constantly moves up and down. It would be a big help if you can show me where it is located.  
         Thank you
         Gary

Answer
HI GARY, THIS IS A EASY ONE TO ANSWER. BUT YOU ARE NOT GOING TO LIKE WHERE IT IS..GET YOURSELF ON TOP OF THE DRIVERS FENDER AND REMOVE THE TOP ENG COVER..NOW REACH WAY IN THE BACK OF THE INTAKE MANIFOLD ON TOP OF THE ENGINE BLOCK ITSELF. NOT THE [MANIFOLD]. THE SENSOR IS MORE ON THE DRIVERS SIDE OF THE BLOCK, WHICH POINTS STRAIGHT UP..YOU WILL FEEL IT,[NOT SEE IT]JUST REMOVE THE WIRE HARNESS CONNECTOR AND FEEL THE SWITCH. YOU WILL NEED A OIL PRESSURE SOCKET TO REMOVE IT..WORD OF ADVISE I WOULD GET A GM SWITCH ONLY.WHAT YOU DESCRIBED IS A FAULTY OIL PRESSURE SWITCH. JUST THOUGHT I WOULD LET YOU KNOW THAT AS WELL...HOPE THIS HELPS YOU AND GOOD LUCK TO YOU,,,TOM.....DO YOU FEEL LIKE A SARDINE IN A CAN YET???...