ISX oil temp

[Boowey1978]

Needing some guidance, ISX 2250 fully de-mandated.... different manifold and turbo. All done 2yrs ago. Always ran little higher oil temp than I thought it should. On a 110 degree day and working it hard I would see 250 degree oil. Now on a 45 degree day I see 250 oil temp. Replaced oil thermostat to a 215 degree. And gauge sensor. If I shot oil pan with temp gun when oil temp says 250 I only get 220 on temp gun. Oil pressure stays bout 35 down road. Water temp 180 all day. What would be some options on to start with. Could the tune be causing this? Any and all help will be appreciated. Thank you