They are the same engine, when O.S. quit the FP they started calling it the LA,, no difference..
Dar is right about the LA not having the boost port. However having less power is debateable. I think it actually has more power turning say a 10-6 prop. The boost port was only an advantage on smaller props. The C/L guys prefer the LA as it runs the 10-6 thru 11-5 props they use better and at a more consistant speed. Just hear say though as I don't own either.