Those temps seem quite low. At what RPM did you see 440C?
I see 630C at the end of the straight at Mosport, about 600C at shannonville.
650-660 you start to melt pistons.
I install the sensor 12-13" from the piston. Your's is at least that far from the port. It will work for comparison purposes but I don't think you're getting a true reading of gas temps.
I have some "K" sensors that are much shorter if you want one.