Do what you want but dont expect to get much love on here for an LS swap. It can and has been done. But I say keep it Ford powered I am not a purist I like stock rigs, wild off road rigs and show trucks. But dont see the need or gain in doing an none Ford engine. Again its your truck do what you want. I also agree an LS or Chevy powered bronco will bring less than a Ford powered one. I have seen this in person at a few Mecum Auctions and I have personally passed on a few broncos over the years that were Chevy powered.
I really dont see the need for all this power in a bronco weather it is a LS, Coyote, or some other high horse power motor. Broncos are meant to cruise and crawl not run the drag strip or do auto cross. Have you ever driven your bronco fast?? They get pretty hairy over 75mph. Sure you can make them handle better and all that but again why? Want to go fast and handel well get a mustang, or some other sports car. Want to cruise in a classic 4x4, crawl off road, and look cooler than any Jeep get a Bronco. There certainly isnt anything wrong with the small block Fords that were put from the factory in our trucks. Mine still has the 289 from 1967 in it and it fires up every time runs 65mph on the highway and can crawl in the rocks. Sure an LS can do that too but why?