Deere 350D pattern changer

Anyone know where the pattern changer would be on a 350D excavator? Dealer says it would be a “field install” option and they can’t tell by serial number if my machine would have one. I don’t see it in any obvious location. Opened the door behind cab can see the pilot lines going into the valve block but don’t see an obvious pattern changer inline. If it doesn’t have one anyone know what lines I’d have to change on the pilot control block to make it have “backhoe” controls ? Thanks