1. Late timing will build heat much faster.
2. If your vacuum increases then your combustion is more efficient.
3. Late timing sends unburnt fuel out of the tailpipe.
Late timing as in what ?
The factory recommended timing setting ?
Say a 1970 340 at 5B TDC ?
Never did I recommend to run initial timing at the stock setting. I recommend between 12-14 as a baseline.
So what's your point in quoting me dana ?