Hola!
Te adjunto a continuacion una guia para bajar el GCFExplorer, con esa herramienta deberias poder conseguir el SDK que estas buscando.
Saludos.
El Tincho JM
-------------------------------------------------------------------------------
GCFExplorer
Developer SASiO
Credits Diviton
Description
GCFExplorer is (like its name says) an application which lets You explore .GCF files and extract their contents. Check the features for more usage of GCFExplorer.
Features
-100% Free.
-No need of .NET Framework.
-User friendly interface similar to Explorer.
-Extract any file or directory from GCF.
-Extract Encrypted files using proper Decryption Key.
-Validate any file or directory from GCF.
-Shell execute (preview) any file from GCF.
-Detailed information about file or directory in GCF.
-Defragment GCF files.
-Fixing GCF header.
-Search for files in GCF.
-Configurable interface.
-Drag&Drop support.
-Recent menu for opened GCFs.
-Detailed log with possibility to save it.
Download
Its in "Attachment", if You dont see it then You must Login.
Download GCFExplorer
Code:
Change Log:
1.23 build 1
- Changed a little bit behevior in tree list
- Fixed exploring tree list with keybord
- Opening files only in read mode share read and write access for other applications like Steam
1.23
-Added possibility to open file/directory via Address box
-Increased extraction process
-Fixed Opening same file right after closing it
-Sorting columans by Name and Size has been fixed
-Optimized decryption algorithm / increased decryption speed :p
-Added time progress calculation
-GcfExplorer now shows App version insted of Gcf version
-Added info if corrupted files has been found during validation process
1.22 build 1
-Fixed RecentList loading and saving when in list exists two same items
-Fixed closing GCFExplorer if previously any file had been ShellExecuted
-Fixed Canceling progress, it will not couse further opertaions to be canceled
1.22
-Added possibility to extract Encrypted files with proper Encryption Key
-Added Progress speed per secound
-Fixed some less (or more) important bugs
-Fixed bug that prevent operations after clicking Cancel
-Improved extracting, defragmenting and validating process
1.21 build 2
-Fixed correct loading of Recent files
-Added check if GCF Header need to be fixed.
-Added Extarct, Validate and Shell Execute options into TreeView menu.
-Last extract dir now will be saved.
1.21 build 1
-Fixed Clearing recent menu from configuration file.
1.21 FirstRelease
gcfexplorer123b1.rar
Download
Filename: gcfexplorer123b1.rar
Filesize: 668.74 KB
(PEDIDO)Source Sdk Actualizacion v26
pro, q es eso? es un extractor de gcfs???, x ahora solo necesito la actualizacion 
Mode Lineal
