A couple of things to look for: You might consider them SPOILERS
James Caan is one of the sailors who picks up Perry Lang and throws him over a table at the USO! (I wonder why he was in this.)
And Mickey Rourke in his first major film as one of Ackroyd's tank crew! Not sure if he had any lines at all.
Slim Pickens and Christopher Lee can both be seen fighting in the last shots looking down into the yard.
Also, there was a great first reveal of John Belushi's character, popping into frame.
It's interesting to me that this came out just one year before "Airplane!".
Personally, one of the best parts was when Treat Williams started to "dance" with Diane Kay. Although the Matheson/Allen story line was a bit long, the low point of the film, was, for me, the ventriloquist dummy.
I enjoyed this film more than I thought I would.