Where is the oil sending unit

I would check your o-rings first before changing the oil sending unit. I am trying to find the exact location of an oil sending unit on a 1991 Chevy Suburban Silverado with a 5.7 L 350. I recently had a major oil leak that we found and replaced. It was leaking from the top of the oil filter housing that is attached to the bottom of the block. The o-ring had busted and was replaced fairly easily. We took filter off, drained oil, two screws holding adapter and housing to block. Now I need to locate the oil sending unit to replace it because my gauge is going crazy with wrong readings as well. Can anybody show me with pics where the hell this unit is? Thanks!!!

oil leaking down the backsie of the block? its attached to a brass fitting near distributor

where is the oil sending unit on a 1995 GMC pick up