With the sidearm style naturally aspirated burners, does it make a significant difference where the orifice terminates in the tee? And, if so, where is "optimal"? Thanks.

I don't use the sidearm burner I use the t- Rex style burner. (I make my own.) But I would think the placement of the orfice would be similar. On mine I like to have the tip just even with the bottom of the air holes. It seems that I get the best performance there. I would try yours there as well seems like a good setting. Hope this helps.

The side arm I had had a set screw holding the nipple/orifice in place. You loosened it and slid it up or down to tune it as needed. Mine seemed to work well with the tip even with the bottom of the opening.