David Barnett
I like the idea of running the larger T-Rex on a lower setting, which in my case, would give me plenty of BTUs with more control range, so when I get to where I can add cullet from previous batches to the raw elements (which cuts my time, op temp and gas usage), I can back it off and save some gas, even if it is fairly cheap these days.

If I can port it into my furnace at an angle which allows it to circle the side walls and wrap around the crucible somewhat, it'd solve the need for two smaller burners on opposite corners of the furnace chamber, which would also save me from buying another regulator and gauge. The other solution, of course, is to port across to the opposite corner, splitting the flame with a refractory wedge, although this would mean designing a larger chamber or changing the crucible diameter and height.

As for tank freezup, I've never had any problems even when running my big burner at 300,000+ BTUs on a 20-pounder so I'm not too worried about that.

Sounds like a single 3/4" T-Rex might do the trick for me, and at only twenty-five dollars more than the Shorty, it's a great deal, especially if I ended up having to add a second Shorty, regulator, hoses and tanks. I'd more or less become impatient at getting this project going, so had stopped focusing on the burners and was looking for more heat-tolerant refractory and multiple tanks to get me closer. Thanks for the useful info. I needed to get my excitement back.