Previously I had tried to install the exhaust tunnel and the parts were not lining up correctly. After a couple of e-mails and some pictures to AviPro it wasn't exactly clear which part had been made incorrectly so Mark Goldberg sent me a new exhaust tunnel, rear bulkhead, and some angle stainless steel for the firewall flange. As it turns out it was the tunnel and rear bulkhead that were off. The new ones fit perfectly. I didn't have to replace the firewall flange. Mark and Budd at AviPro are great to work with and quick to respond when an issue like this arises.