New verb principal part?

[Arnold Zwicky]

various folks are citing nonstandard preterites ("strong" where the
standard form is regular, regular where the standard form is strong,
or a strong form different from the standard strong form) from the
rural south.  this could go on for a long time; i could dredge up some
colorful family stories from the mountains of eastern kentucky, for
example.

but have there been some systematic surveys?  wright's English Dialect
Grammar goes on at some length with similar examples from england.  it
supplies an inventory of nonstandard forms, with a list of counties
for each.  this is not as much information as you might want, and it's
hard to discern patterns, linguistic or geographical, in the lists,
but at least it's a start.

(as is usual in such situations, sometimes it's the standard that's
innovative, sometimes the nonstandard variety.)

is there at least this much for american english (or some region)?
not that i don't enjoy the anecdotes...

arnold (zwicky at csli.stanford.edu)