I'm getting ready to install a FS2500 filter on my truck and I'm looking for alternatives to the drain-plug removal/replacement option. I've heard mention of some guys plumbing the return back into the oil fill cap, but I was looking at that this afternoon and had another thought. Has anyone ever removed the oil fill tube, drilled a hole in the body of it and welded in a fitting?? I'm thinking about trying this and wanted to get some feedback before I dove in.

Thanks!!

I've heard of some doing that with a swivel fitting so it spins. AMSOIL has a fill cap replacement that you should be able to use. Just hook your return hose to it. Here's the description:

General Motors 6.6L Duramax Diesels
Like the other diesel applications, AMSOIL now offers an Aluminum Billet Oil Filler Cap for (BK1202) to ease the installation of the oil flow from the BMK11 back to the engine.
2. Aluminum Billet Oil Filler Cap for GM Duramax (BK1202)
3. Two 90 degree JIC Elbows (BP242)

Let me know if you would like more info on these.
Heath

You can just drill and tap it there are link to pics in my garage on the 06s+.

Filtration Solutions (FS2500) is just about complete with their filler cap return. They were awaiting the anodizing on the caps, and are moving into a new building (hence the wait). They are using a filler cap with quick disconnects. It should be available in a month or so. I am not sure if it will retrofit the older hookups. Maybe just a new hose to fit the cap.