Now that the 120's have arrived in the States, I've seen alot of good info on this plane, but can't find what I'm looking for about engine/muffler mounting issues.

I've got a Saito 150. The stock muffler connects to the engine with a 45-degree angle threaded pipe. The plans call for a 1/16 to 1/8 inch clearance between my spinner backplate and the cowl. To make this happen, the muffler is up hard against the bottom edge of the firewall.

1. Should I go with it as is, and maybe carve a little channel in the bottom of the firewall to let the muffler clear?
2. Should I go with a Pitts-style muffler? Will this clear the firewall?
3. I ordered a MACS muffler extension. This has a 90 degree bend off the engine, then 9 inches of flex steel tubing, then I can connect my muffler to the end of this. He said I can put all the turns I want into the tubing, but this will still put the muffler well up under the plane. If this is the way to go, how can I secure the muffler to the airplane to keep it from flopping around.

I know this engine works great on this plane. I'd like to hear how others have made it all go together.

Thanks for the help.

B-ski