SomeBody writes:

Any tips, comments, suggestions?

Propane will work up to a point.

I've done some larger pieces with the added heat of a Reil burner like you
describe. You're probably right on the edge of getting it to a high enough
temperature. Try clamping up the big Reil burner to heat the piece
overall, and then apply the biggest hand-helf torch (e.g., Turbotorch, yes,
a 2nd torch) you can find to the joint.

Also make sure you are using a low-temp alloy brazing rod.

Get a jar of some good commercial brazing flux. It will work better and
easier than improvising with borax and such.