I did replace mine on my MC7205 it wasn't really all that bad. You mention 140 lbs. is it the 352? One other note I did call McIntosh and had them send me the service manuals which cost me about 10-12 each. I also had them send me the bulbs. One note is make sure the caps are drained. I ran the speakers at about half volume and unplugged the amp in play to let the caps drain. These can set you back on you pa-tu-tee if you short one while working on it. Also be prepared to solder some very small bulb plugs they do not slip in and out , they must be heated to remove.