I have a GP Christian Eagle II and a Brison 3.2 to go in it. I have not purchased a muffler yet but thinking of going with the Bisson Pitts or the inverted. Does anyone know if the pitts style will fit without modifying the firewall? If the Pitts will fit, do I need the 15 or 45 deg.

Thanks

Had that exact set up. Loved it! I used the Bisson 15 on mine. no problems.