I can live without my test stand, and used to break engines in on the planes, but not any more. I have an engine break-in mount that can be c-clamped to my wooden ladder. (usually the third rung up to put it at the right height for me). The best part is I can mount the stand horizontally by c-clamping to the side of the ladder, or inverted by c-clamping to the bottom of the rung. While the engine is running I can go behind the ladder and tilt the whole ladder and stand to point the engine vertically and witness the leaning effect. Works like a charm! When the engine is relocated to it's plane, I have never had to adjust the high speed more than one/two clicks to optimize. Saves a lot of time at the field; I just range check, start the engine, double check control surfaces and I'm flying - not adjusting and experimenting while holding up a frequency that someone else might want to use.