Is a front end alignment required when a 2" rear drop is done ?

 

An alignment can never hurt (unless you consider the damage done to your wallet). Correct me if I'm wrong, but F150s have a 12,000 mile alignment warranty. I'm getting close to this point now so I'm going to have an alignment done and the camber adjustment done for free under warranty.
I by no means am an expert, but to answer your question, I do not think a front end alignment wouldn't be required when adding shackles to drop the rear 2".
-Michael

 

Nope. You will be just fine