I called ATS this past fall and spoke with one of their sales reps about their different turbos. I was actually trying to get compressor maps out of them for the A3k 4k and 5k, but those guys wouldn't come up off them.
Anyway, during the conversation I asked him about the A3k for my LLY and he said that they were discontinuing that model because it's not enough of a difference between the A3k and the stock charger and basically they don't sell enough of them. I don't know if he was just buffaloeing me or what, but that's what the guy said.