Thank you for contacting Intel Embedded Community.
The KU80386EXTC33 has been replaced by the QU80386EXTC33. You can confirm this information on page 7 of the Product Change Notification (PCN) 104316.
By the way, the QU80386EXTC33 has been discontinued. This information and more details can be found in the PCN 106013.
Also, please review the attached document.
We hope that this information may help you.