there was an article, hotrod maybe, where they put a t56 in a 68 or 69 charger. google it. they had some good pics of what cutting the corssmember looked like.
i keep coming back to it for my 67 coronet, i could cut and weld up the crossmember but i will probably just keep a 727 in it...less work and money and i don't mind autos i guess.