Underwater Kinetics UK D8 -- LED equivalent?

I have an old UK D8 in top condition (only 3 dives with it), which has dual incandescent bulbs (if one burns out, you can rotate the other into position and continue having light). It worked really well when I used it on my last dive, which was 3 years ago (economic downturn put a dampener on vacations for me). The 14w Xenon bulb puts out a good 300+ lumens and will last for about 4 hours before starting to dim, running for another 3-5 hours of usable light. This is also a warm light, which has excellent visibility.

I briefly looked into the possibility of an LED upgrade, but any posts I've found across the Internet are usually started by people with few posts to their names, who take a few posts of advice from others, and never return with even a progress report on the attempt.

Is it feasible or worth doing?

UK has an LED conversion kit for them already - I looked into converting my C8, and was told the kit (which includes the reflector, and I believe the entire 'front end') was about $46.

Ah, good to know that. Thanks!!

you are very limited, due to sealed body and no way to dissipate heat, if you really want bright upgrade you need a light build around the led, not a led in a casing that was not made for it. bulb reflectors usually do not let leds shine to their full potential. UK makes agua sun eled light, build around led, with proper heatsinking and optics.

^ I'm not so much concerned about an increase in brightness as much as extended runtimes. If the upgrade can provide that, it would be worth it to me.

You should be able to handle 4W on an LED in that housing. That would give you slight improvement in light (assuming you get a good LED) and much in battery life. Unfortunately it's probably a custom job, unless you get the dropin from UK.