Stock 03 f150 stx wanna swap to a lightning motor do I have to change the trans and diff

 

What engine is in your STX?

Lightning came with 4R100 and 9.75" rear.
STX 4.2 came with 4R70W which will NOT work on a V8 and a 8.8" rear.
STX 4.6 came with a compatible 4R70W and 8.8" rear.
STX 5.4 came with a compatible 4R70W and 9.75" rear.

A 4R70 PCM cannot run a 4R100, and vice versa.

 

its a 5.4

 

Trans and diff should be strong enough, but don't use a Lightning PCM, get tunes for yours.

 

Thx for the help

 

Thanks

 

Glc for the win