You will need to change Blender to use Imperial/Metric units, then there is a way to also show the measurements while working with the model. I dont remember where the setting is right now (2am), but here are a few tutorials to point you in the right direction. Also, use v2.79 as Xplane2Blender is not supported in Blender 2.8
https://docs.blender.org/manual/en/latest/interface/ruler_protractor.html
https://www.katsbits.com/tutorials/blender/metric-imperial-units.php
https://blender.community/c/today/6jbbbc/