I began working on the firewall this afternoon. I bought my firewall from Zenith because the raw material to make it was almost as much as the completed CNC-drilled part. (Kind of a no-brainer.) Everything looks good so far. I'm sure once all of the stiffeners get in place things will firm up. Right now it's hard to imagine a 200+ pound Corvair engine is going to hang off of this. As you can tell by the picture, the cat continues to be intrigued.