Tranny: 5R55W to 4R55W? Yup! Backwards!
 

I have a mechanically perfect 1996 Explorer Sport with fine 4R55E tranny. The problem is.... It has been rolled. I can buy a 1999 4D in beautiful cosmetic condition that has a NO REVERSE bad tranny. So can I put the 4R55E in the newer 1999 and what problems will I face if I can? i.e. computer, drive shaft length, etc. I thank you, Gentlemen!
.