Paul,
I have read that the c4 is a great tuck and fit for the stock 46 crossmember so I am 80% sure this is the direction I will go.
I went on the TCI website the other day and they have a fantastic dimensions page that gives full dimensions for most popular transmissions. It claims the AOD is only a tad longer than the small bell housing c4 (like i have in my T) the only differences is the transmission mount is 2 inches further back compared to the c4. which would put the mount further back in the x member. Like pops said we do have an AOD out of a Grand Marquis in the shop. Might be worth bolting up to my 302 and seeing how it fits.
Don Jr.:)
