Just a short update on the build.
I replaced the carbs with some older ones (with 105 mains) because the PD carbs were not able to be tuned to my liking. The older carbs worked great out of the box.
I pulled the plugs after some 20 miles, and they all look good; no soot or white chalk, just some nice tan color
I broke the engine in with the sidecar in place because I let my M1 permit lapse and you don't need a motorcycle license to ride a 3-wheeled vehicle in California.
The bike pulls hard in the midrange and has no flat spots during acceleration.
Only issue I've noticed is it gets very hot during freeway rides. I think it's a combination of the big bore kit and the extra load from the sidecar.
I will add an oil cooler with a built-in thermostat as soon as I can find a location for it as the sidecar mounts are in the way.
I have had a few issues with oil leaks from the tach gear, rocker covers, oil pan, and shifter shaft. Most of those have been resolved except the tach gear (started another thread)
Anyhow, I am really enjoying the extra power and would recommend the upgrade to anyone with a 550.