Changing a Transmission...What is involved?
The transmission itself should be a straightforward "bolt-in", since the 351W shares the same bellhousing bolt pattern as the 302. You didn't mention the year of LTD, so I'm assuming you are referring to a pre-1980 model, since that was the year Ford introduced the AOD transmission to its line-up of rear-wheel-drive mid to full size models. You will need a pilot bearing for the crankshaft. You will also have to fabricate a shifter, as well as all the hardware to mount a clutch pedal and linkage assembly to make it work, since a manual transmission was never offered on a LTD. The driveshaft may need to be altered.