What is the difference between the 4R100 in an Expy and the 4R100 in a Lightning.....If I put the supercharger from a Lightning onto my 5.4 Expy motor, will my tranny hold up to it, or do I need the Lightning version of the 4R100?

 

The only difference I know of is that the lightning has different springs in the damper of the torque converter. I don't think that will cause you any problems.
Alan