o.k.
for guys who don't use vac advance and have a lazy curve ...say 35 degrees total all in at 3500 rpm
..they may very well be running 25 degrees total when cruising 50 mph or about 2500 rpm
with 3.23 gears,so just poor economy?
In my experience, yes.
It makes for a lazy motor and less than optimum fuel economy.
The more BTDC you can light the fire the more efficient the use of the available fuel, and of course lighting farther before TDC comes into play with RPM's