I use the KY Mousse cans from Flying Z hobbies. They aren't very expensive, even counting the $20 for the mac's header. I get over 2,000 on my Mag .28, they tac over 18k on the ground with the MAS 9x4. And that's with no modifications to the engine besides the can.

Get the "OS" header pipe. The Mag bolt holes are very close to the OS .25FX, but not quite. I then take a drill and ream out the holes on the crankcase just a hair. We are talking a small enough reaming that you can't tell if it's been done to the engine or not until you install the pipe. It just takes a moment.