Lumen output of SF L4 - 65 or 100?

I'm wondering before I jump...I have the 2005 SF catalog pdf and it says 65, but the surefire.com site says 100...and some sites say 65 too...help? Thanks!

Surefire tends to underrate their lights. The A2, for example, is rated at 50 lumens, but McGizmo found it was actually 79 lumens. I suspect that within the L4 line there were some lights that were perhaps only 70 lm., and others that were 100 lm. Now with the bump up in lumen rating, I think Surefire is practically guaranteeing all that L4's are 100 lumens.. or more. The L4 is rather floody, though, so it "appears" less bright than an E2L because the beam of the E2L is much tighter. The L4 still puts out more light, though.

That answered my question quite well. Thanks!

So, if I get an L4, can I buy a head for the E2L or even an incan head to put on the L4 body if I want more throw?

That's right. The E2e, E2L, and L4 are all the same light except for the names engraved on the body and the head-- using the E*e bezel (available at lighthound.com), KL1, and KL4 respectively.