where is my oil pressure sending unit?! On my '75 blazer with a 350 I am assuming it's the cylindrical thing threaded into the left hand side of the block between the spark plugs (numbers 1 & 3 i believe). I scoured my Haynes manual but found no info. And in that vein where is my coolant temperature sensor? All I see in my thermostat cover is a plug threaded in.