I ordered the P7 led and the heatsink from members there. The reason for doing the mod, pardon the pun, is night and day. The new generations of led flashlights have an incredible amount of output, this conversion should make the light roughly ten times more powerful than stock as far as lumens go. A heatsink is necessary or the led would burn up in short order. I chose to do the 3D conversion because a led driver board is not necessary at the voltages you get from 3D cells. 3.6 volts using 10,000 mah nimh D batteries should yield quite a long run time. I'll document that after I get there. Going back to driver boards, they are available and would make the light do some fancy things, vary the output levels, incorperate an automatic s-0-s beacon, and a strobe, among other effects. I ordered the Arctic Alumina heatsink/epoxy from outpost.com.