Just out of curiosity, why?

There's a myriad of easy ways to fly from LAS to NYC, both nonstop on other carriers and with easy connections in ORD/DFW/CLT/etc. if you want to stick with AA.

As noted if you're on time then you should be ok. But routing that way seems like a huge hassle with separate tickets on separate airlines and risk of misconnect, landside terminal change at LAX, lugging your checked bags around, etc.