I did a product change with Chase, in August 2007. My account number and credit history remained unchanged.
When I had a Capital One account (I closed it in November 2007), they changed my card from a non-rewards card to a rewards card (I did not request this change). My account number changed, but my credit history remained unchanged.
Do make certain to ask the CCC's customer service representative about how the product change will affect your credit history.