Question If I pull out and aod floor shift from an mark 7 or mustang will it fit in my bird?
Yes it will. If you use a Lincoln AOD the tailshaft is longer though, meaning you'll have to get your driveshaft shortened. The Mustang AOD is the same length as your stock one.
cant you just change the tailshaft from the cougar to the lincoln?
The LSC shifter is waaay different from the Bird/Coug piece(at least my old '86 parts car was). I took one look at it and said %@!$ this, it went away with the car to the crusher. I haven't really looked at the Mustang shifter, but I would think it is similar to our cars.
The tail housing ain't a problem to swap, but it requires total diassembly of the tramsmissions to swap the inner mainshaft that is also longer on the Linc tranny. I have heard of the end of the shaft being sawed off, and then being rebeveled with a file.
The mustang shifter is straight and the ones fot the cougar/tbird have a bend that brings the shifter closer to the driver. On the underside I don't know.