Surefire E1 Modding

Need a little help here please. I have recently acquired a SF E1 series light. I have 2 different heads. The first is a KL-1 head with what appears to be a luxeon led. The other head is just the bezel and reflector. My questions are as follows..

1. What emitters and drivers can I swap in the KL-1 to more runtime and better output?

2. The second one I have to make a drop in for. Someone sent me rough dimensions for the sizes but they were rough.lol Made a test piece and it doesnt fit. Anyone here give me more info on sizes, drivers, emitters and the such that will fit?

Thanks!

Which version KL1 head? Early or late? Is it from an L1/L2? Knowing these things might help. As far as improving the output and run times, you'd be hard pressed to improve runtimes on this one as it's a low level long runtime head. Changing the LED to a newer, more efficient one will improve output and might slightly decrease run times due to the lower Vf.

With regards to the other head, is it a standard incandescent head? There are a few drop-ins on the market for those already from Steve Ku and a new operation from Malaysia called S1ngle or something like that. If you are making a drop-in for it why can't you make it fit?