Yes, you can do.
Sometimes, they stamp the I-555 at the port of entry as in the case of my colleague and plastic cards automatically come by mail without you bothering to go to INS office. Some other times, they do what is called deferred inspection. You will be let in with AP and once the approval letters arrive, you would have to get your passports stamped at the local INS office and then go back to the port of entry to show them. Your name goes onto database that time and you receive your cards coolly later.