727 output shaft/housing?

Hi Guys,

I scored a good 727 for $50 this weekend, but its out of a truck,(short output shaft and housing, 1975 1/2 ton). I would like to put this in my 64 Dart, but I know I need to change the rear housing and output shaft to the long skinny style. Has anyone done this, and do you know if those parts might be available somewhere?

Thanks!

Tom