Can someone please tell me where the oil pressure switch is located on my 86 z28?

I found the gage sender on the back of the block, but the oil pressure switch is not in the same place as it is on my '89 (on the block by the oil filter).

Is it possible some of the earlier tpi's didn't have one?

 

They are both at the distributor, single wire for the gauge and dual wire for the fuel pump.

 

I found it,

Thanks MadMax