I needed the data from engine and propeller, so I just took pictures of their data plates! I also made the needed measurements for the W&B calculations. Using a recently calibrated industrial scale, I also took weight measurements of the main landing gear and nosewheel....I'm going to have a heavy Sonex at 713lbs. Oh well, that's why I went with the Jabiru 3300. The weight measurements were done with only unusable fuel in the tank, Full oil in the engine, and the cowl installed.