Frederic G. Cassidy (ed.), Dictionary of American Regional English, vol 1:
ax v, ax'd, axe, axed See ask A
1 pres: usu ask [æsk]; also:
a [æks]. Pron-ssp ax, axe [OE ascian, acsian: see OED ask, etym note] formerly esp NEng, now chiefly Sth, Midl
For the 20th century, quotations are from: KY, central PA mountains, MS, western NC, eastern TN.
It's interesting that the two pronunciation ask/aks were apparently interchangeable (to some degree at least) all the way back to Old English, i.e. 1200 years ago.