I have several E2Es. I have one set up with the LF drop ins and I run the 17670s. It works great. Why not do that?
Just to add to what Scout posted. The Tana TNT single is WORTH the money. The E2E is WORTH the investment. Get the TNT with Dr. Jones driver and some 17670s and you have one hard to beat package. Just sayin.
Skip the spacer stuff and have increased capacity.
This thread makes me think, I should probably take some beam shots between the LF & TNT for folks. Only problem is, there are so many different TNTs available. It's kinda hard to compare evenly, I guess. For me, the DrJones driver and led options makes all the difference.