Took my first real ride with the new exhaust on there, and this bike sounds disgustingly mean. I used some clever shimming, and manhandling while clamping and got it 95% sealed up. A new set of the thicker, silver/blue gaskets await me at my parent's house, and I'm confident those will do the trick. The copper gaskets have less mating surface, and are a little wimpy for this job. I've got all sorts of minor popping on deceleration, so I know that carb tuning is in my immediate future. These carbs need a good cleaning anyhow, so it's good timing.
I think I'm going to have Chris make me a pipe for my 750. The sound is addictive.