I've finally decided that the #64 jet with the needle in the second from the top slot is gonna be the best compromise for my NT Speed carb. It pulls strongly at the bottom end with very minor 4 stroking at a 20 mph cruise, and nothing but 2 cycle fury at wide open throttle. After a 3 mile run at no less than 35mph, the plug chop showed a very light color of tan --- couldn't ask for better.
Gonna leave the current exhaust on it. I did wrap all the conduit joints with FiberFix. This is a fiberglass type material with epoxy embedded in it --- very easy to use and drys rock hard. While the joints worked reasonably well, they did leak a small amount. The FiberFix will seal the leaks and prevent any of the joints from working loose.
I'm glad that I haven't had to rely on the bike for transportation, as it's taken me 2 1/2 years to get it to this point. Maybe the next build will start with better components, but where's the fun in that?!