Let me give you some feedback why I tried different attitudes on ground.

First I put two tanks for break in on the ground, then I and went into the air!!!
For the first flights I added a button to offset the throttle so the engine would run at 3k at idle and the turn it off just for landing.
I adjusted the idle to 2.5k with no problems on the ground.
Third and fourth flights, using the throttle offset (3k) 6 minute flight ended dead stick.
So I think: OK maybe my adjustment at idle was not good...
I verified the idle and everything was just O.K. for the test I leave the idle from 30 Secs to around two minutes and apply full throttle
with no problems at all.
I went to the air and ended with dead stick, so I tried two more flights (that also ended on dead stick) looking for the flight path used when the engine dies. and thats how I ended checking the attitudes...

After some more tests I think I'm around 10 tanks