Right, in '68 they (Chrysler) 'farmed out' either 48-50 Darts to have 426's installed for sale/use by professional drag teams, prior to that there was no such effort. There might have been cars that had Chryslers 'blessing' prior to '68, but , they were not directly, or , indirectly involved.
My friend says he saw a '66 Barracuda, with a 426 that was the result of Chryslers involvement similar to that of the '68 cars.
Anyway, thanks for the response. I know there are people on here that will know the 'exact' history of 426 A-bodies.