Well, maybe I can answer my own question... According to the Lumensfactory website the EO-6 will work in my Surefire C-2 or M-2. If you have a different opinion or can add any info, please do so. Thanks!
There will be no different opinion. The lumens Factory 6 series are designed to work in flashlights that use the P60 or P61 lamp assemblies. That includes the SureFire C2.