What I found was the bushings all allowed to much advance for the initial that my engine needed. My engine ran best with 34° total and liked 22° initial. If I set the total timing it wasn't happy at idle and if I set it at idle it had way to much total.

There was a member here that made custom bushings so I bought one and sanded it down to get the right amount of advance. It's been years ago and I can't remember who it was.