[nytrainer]

You are using manifold vacuum for the distributor advance then when you unplug it from the distributor you must plug the hose with something, I use a golf tee because it's tapered, otherwise the RPM's will raise and you're not setting your true initial timing. You are introducing some centrifical advance when its not at idle. so look at the instructions again and try to follow it setting your initial then you could check your all in. We can go from there.