Riddle me this, Batman!

It's stock except for a comp 265 deh cam, headers and a Holley vacuum secondary. 0.030 over. It's running good on the stand.
This cam/engine combo, as do all street combos, will want different timing with changes in rpm and load. There will be times that it may want maybe as much as 56* of advance, and other times that it will be happy with just 5*.
If you lock the timing, it is good for one thing only, namely WOT DragRacing. The timing will be dead wrong under all other circumstances.
On the street, you will get best results with a factory-type vacuum-advance distributor; and the vacuum advance is gonna need to be modified and tuned as well....... cuz how do you get from 35* Power-Timing, to something like 56* cruise-timing?