OK lets reason a little here guys.
I made my statement about checking point situation first based on personal experience with these older engines non-professionally maintained until necessary and I find:
* timing is unlikely to change in normal use unless points close up or (rarely) the distributor slips it's restraint.
* valve setting are slow to change and usually exibits increased noise and until very loose don't effect performance very noticibly.
* dwell changes normally only when point gap changes.
*vacuum advance malfunction only affects acceleration when a small air leak is created by the ruptured diaphragm and really only effects performance at light loads because it starts to retard as load is applied/decreasing vacuum strength.
My case rests.
