Suggest you look at the StrongRCMotors and page down and look at the winding chart.
It's essentially the same motor.
Here's my few winds experience:
GBv: 15T/24g newbie wire - Y
KV with faux prop:
1767/1773/1774/1770 – Pretty good consistency.
GBx: 25T 26g newbie - Wye (GBx uses the same stator but has more room front to back).
I also tried this and still fly it on a small stick plane with success:
GBv: 35T / 28g newbie Y = 750KV (x 1.73 > 1300KV)
10890/7.91 = 1376 delta measured
15870/11.56 = 1372 measured
I terminated it delta and fly it with an GWS 8x4 HD on 3S.
You can only get 2 layers on the GBv or you end up rubbing on the can. That's why I tried the high wind # of 28g. You can put a tiny spacer in there and maybe get 3 layers of fatter wire (26, maybe 24) in.
Don't have efficiency or thrust data. There used to be a discussion forum with that data at GoBrushless but I couldn't find it. It wasn't very active anymore.
Have you seen this thread?