Adjust initial timing for highest vacuum at idle. Generally where the engine is happiest, although that doesn't address the timing curve. I would set for best vacuum, then see what the all in number is at 3500 or so.
As a kid without a timing light back in the day I'd advance until it started to ping and then back it off a couple of degrees. Probably was about as close as a fellow could get it without a light...and everything I timed that way ran awesome.
As a kid without a timing light back in the day I'd advance until it started to ping and then back it off a couple of degrees. Probably was about as close as a fellow could get it without a light...and everything I timed that way ran awesome.