Yeah. I got an ECB and did similar mods and turned out some very tasty Q. I only built my drum to get more space.
One problem I had, I used really thin sheet metal for the bottom damper. After a cook or two, it would bend and curl with the heat and not close properly. I think if I used thicker metal, it wouldn't have been a problem.
Proudly Smoking on a UDS, PBC &
Accidental Winner of the 2012 "Saucy" Throwdown.