Originally Posted by
KARFA
In terms of first and business the only routes with actual first selling classes are JFK-LAX and JFK-SFO which have the three class A321s. If you book on those with your I class sale fare you you will be in the business cabin and earned business TPs. All other AA domestic flights just have business selling class for the front cabin although they call it domestic first.
Just to be pedantic, MIA-LAX operated once a day with a wide-body (otherwise narrow body with the usual recliner seats) which nowadays tends to be either a 77W with selling F class (done that a few times) or 763 with proper lie flats in Biz.
If it's I class the OP would needs (and they still want to travel vie LAX), it's pretty difficult to find these days on JFK-LAX, so MIA might be an option.