From the beginning of running the GT33, in 2011, I set the needles pretty much there and have made only slight adjustments to the HSN to accommodate the large props that I use. I mean slight, like the width of a screwdriver. 4% mix is very oily. I use 2% mix (50:1) for break in and regular running; no need to change the mix. I know that some people do but it isn't necessary if you use a good oil. I use an excellent synthetic from the start for break in and after.
For 3D you may want to reduce the prop load to a 19x8 or 20x6. Use apc props as they are the best: best means they are the most quiet, converting more power to thrust
Do yourself a favor and lean the needles. Gas engines don't require the slobbering rich break in of glow engines, ever, during their lifetimes. Very slightly rich for the first couple tanks is fine. That means HSN 1 11/16 and LSN 1 5/16 open from fully closed. Even that is probably too rich. Your transition will cough and sputter but the engine will continue running.