That's a sweet install. Big block I'm guessing uses a little bigger tubing as well than most FAE installs. 3.5" tubes on each side? Nice job.
Wonder if all 8.1 users encounter the same problem. Like all boat exhaust ports start the same size from the mold and then the manufacturer hastily bore the holes bigger (and uneven) to make big blocks exhaust fit. Weird that they'd be oval.