Oil Sensor Location on BX1860

I have a new BX1860...Great lil Tractor... I would love to have an oil pressure gauge to indicate what the pressure is before I do the first service on it to see if a different oil is gonna affect the pressure..... where is the oil pressure sending unit and sensor on these engines?? Has anyone put a gauge on their BX series??? I can "find it by diggin and lookin'... but would rather get it from someone who has done it .... and what kind of problems have they encountered when putting the gauges on....I appreciate the help Guys. This is THE BEST Forum I have come across!