I was under the impression that all the current 4003's with the new bridge are single truss rod. No doubt someone will be along shortly to tell me I'm wrong.
Had to do a set up on my 4003, where I had to adjust the truss rod (yes, had to stump up and buy the tool). Was a bit cautious admittedly, just adjusted one a quarter turn, then the other the same amount. Thankfully, they didn't need too much adjustment, and it's still a great player. Even the intonation's spott on.