Boy are we late on this one. Sorry, Junior, but from some quick searching for parts, it seems that they should be. Some sites say GMC or Chevy, and it wouldn't surprise me if they are indeed interchangeable since so many GM truck parts have been that way for a long time.
Might want to ask the seller for pictures just to make sure. They might help your friend make his decision. If the friend has already resolved this issue, let us know. Tell us what you learned.

Hope that helped.