There are plenty of threads on how to convert a 2D mag into a 6AA ROP complete with sources for parts.
There are a lot less info on how to build a big die LED torch. 3D yes, 2D no.
outersquare, can you provide a link for GunAround on instructions on how to convert a 2D Mag into a big die torch. Complete with sources of parts.
I had a 6AA ROP a year ago but i wouldn't bother building another now.
it costs alot to build correctly, it's not particularly bright esp compared to big die LEDs and it has crappy runtime esp for the larger size.
It is brightest the first 5 mins you use it then it dims alot.
imo a waste of money now.
GunAround:
Due to less interest in the ROP nowadays, it is harder to get parts. So do not start until you know you can get everything.
For LED drop-ins.
Mag LED upgrade kit for 2 cell flashlight. Available where Maglites are sold.
Terralux TLE-6EXB. Available at LED-replacement or Battery Junction.
Both the above drop-ins will drop to half brightness in ~10 minutes.
Malkoff Drop-In Module for the Maglite® 2-3 D Size Flashlight. This one should stay at full brightness for extended periods. You will have to cut off the cam off your
reflector.
Now for the big die drop in.
Malkoff D Size P7 Drop-In Module for Maglite® flashlights.
You will need
Mag 2D, 3C to 18650 Adapter Kit, 2 AW 18650 protected batteries and charger. An orange peel reflector is recommended for the smoothest beam. (I ended up buying one for my Elektrolumens 3C P7 mag)
At this price and complexity point it might be better to buy a new light.
If outersquare cannot find a 2D mod but a 3D one you can convert your 2D into a 2D head 3C cell body with the 2D>3C>2*18650 kit above or make your own with a piece of 1/2" plastic electrical conduit.