RE: KMP Edge 540
The opening in the cowl is not level (it's not supposed to be!!!) because the opening is angled to match the right thrust so that there would be a consistent gap between the cowl and the spinner when the right thrust is factored in.
You don't want to move the engine up because you don't want to work on the firewall... That's too bad. You will end up with a plane with the incorrect thrust line and will more than likely end up with some serious coupling issues.
You stated that you want to mount the engine centered on the marking on the firewall. What you need to realize that the engine must be positioned so that the HUB is at the centerline, not the rear mount. The firewall has the necessary built-in right thrust (that is why one side of the box is longer than the other). The cowl opening is at the centerline of the airframe. Center the engine hub in the cowl opening and mount the engine to the firewall. You will end up with a very good flying plane with the engine mounted exactly where it needs to be.
Why to I know all of this? I HAVE ONE OF THESE PLANES THAT I HAVE BEEN FLYING FOR MORE THAN ONE YEAR. I set it up exactly like denny47 did his. It works just fine. Quit being so hard-headed. You are making things much, much more complicated that it needs to be.
You came on here with a problem and denney47 has given you absolutely 100% correct answers and you just choose to ignore him. I can understand the frustration in his last post.