I need to find out if it is possible to bolt up a 4r100 out of a f-250 to my f-150 with no modifications to the engine of transmission, and make the computer still work correctly?

 

The trany will bolt up with out changing anything but you will have to have the computer tuned for the 4R100 to operate it.

 

The ONLY way you can control a 4R100 is with a PCM that came from a vehicle that originally came from Ford with a 4R100 - period.

You cannot mix & match PCM's among different automatic transmission with FoMoCo vehicles.

Now you CAN do things like put a manual transmission into any FoMoCo that had an automatic and changes things in the PCM so that it will work - it simply thinks the vehicle is in neutral all the time, basically.

But you CANNOT mix & match automatic transmissions - I.E., a 4R70 can only be controlled by a PCM from a vehicle that originally came with a 4R70 - same goes for 4R100, same goes for 4R75E, etc., etc.

This is how Ford delineates their PCM's, is by transmission type, in terms of the automatic transmission vehicles - you get a 4R100, you get a different PCM than you would if you had a vehicle with a 4R70, and so on.

So if you are going to change automatic transmission type, I.E., going from a 4R70W to a 4R100 - you will need to change the PCM & the harness, too.