Computer reprograming with a new 4l60e heavy duty tranny???

Hey guys, my 4l60e transmission in my 97 silverado z71 went this weekend. I am looking at putting a heavy dutty tranny in it. My question is, do I have to reprogram my computer if I do this swap? The local dealer is telling me that I will have to. Any info would help...thanks
Jordan

here is the tranny I would like to put in.

http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&category=33727&item=2461072404