This is a picture of the setup I use in case anyone was interested in trying it. I changed it up from the picture. I have two pieces of 3/8" x 2" wide that go across with a patio block. Then the two heads sit on the patio block so that the burner flame isn't right on them and then the garbage can sits over the heads to help hold the heat in.
I originally didn't use the patio block and it was hard to keep the heads somewhat uniform. Now There is maybe at 15-20*F temp difference from top to bottom.