[davepl]

Remember, no vacuum advance at idle. If you've got any vacuum advance at idle, you're either connected to the wrong port or your throttle blades are too far open, uncovering the transfer slots.

Problem with the timing approach is you can usually increase vacuum a lot by over-advancing base timing. More of a crutch than a fix though. It has been my experience, however, that cars need/like a lot more base timing than the old tuneup stickers say.

My 402 prefers 12 degrees, a lot more than the (4 or 6 maybe?) that the sticker calls for. People say it's because gas is different, I'm not really sure.