Steve,

I don't own any Zenoahs, so I'm not sure what you'll be faced with when you go to install that muffler.

I can provide you with measurements from my plane/installation (firewall to cowl opening, depth of cowl, etc...). That way you might be able to pre-determine whether your wrap-around configuration will work, and whether you'll need stand-offs of a specific length. I will say that the cowl is not very deep, though.

Let me know if you want me to take those measurements.

Noah