Two hexagon hot ends (both brand new) are different lengths

[kfahn]

So I am in the process of putting together clough42's dual extruder so I ordered two hexagon hot ends. Unfortunately the two that I received are different lengths from the heat sink to the heater block. More specifically, they are 0.84mm different in length. You can see this in the picture below. I emailed Colin over at Makerfarm since I bought both of them from him, but haven't heard back yet (jeez, it has been a whole 10 minutes). Does anyone know of a way to safely modify the length of the pipe which is exposed between these two sections?



And to answer other questions that may come up, they are both completely unused. They have set screws on the side of the heatsink, but I can't seem to figure out what those are for.

Any help would be much appreciated.