RE: God, I Really Can't Tell!
My gear looks exactly like the one in the picture above. What I did this morning was to take out my tape rule, back the tail wheel up against a stop and measure directly from the stop to the center line of the landing gear wheel shaft. Exactly 36 inches. Turned the gear around and took the same measurement. Right at 36 1/4 inches. I'll leave it in the 36 1/4 position and give it a try.
One other question (looking for opinions here I guess). The previous owner had an OS .91 4-stroke on this plane. I was planning on using a Thunder Tiger .91 4-stroke that I already have, but, I have an opportunity to purchase a used Magnum .80 4-stroke for this plane which I'm considering because my style of flying tends to be slow and easy (read "scale") flying. I'm sure being retired has something to do with it, but I prefer to just lazily cruise the sky. Don't have any experience with Magnum engines, all Thunder Tiger and Saitos so far. Any thoughts on the Magnum for this plane would be appreciated.