First time when you distribute the pkg to distribution point then SMS/SCCM chooses the NTFS drive which has maximum free space.If you have 2 to 3 NTFS drives and you want to chosse one of them;then there is no provision given at SMS/SCCM server side. Create the text file on the other drives with the name NO_SMS_ON_DRIVE.SMS which will prevent respective NTFS drive from creating SMSPKG<drive letter> folder.Drive which dont has NO_SMS_ON_DRIVE.SMS file,will have SMSPKG<drive letter> folder.If you want more information then search on google with NO_SMS_ON_DRIVE.SMS
http://technet.microsoft.com/en-in/cc678050(en-us).aspx (SCCM 2007 IBCM & Native Mode)
http://technet.microsoft.com/en-in/cc678049(en-us).aspx (SCCM 2007 Desired Configuration Management )
http://technet.microsoft.com/en-in/cc678048(en-us).aspx (Software Updates Management with System Center Configuration Manager 2007 )
http://technet.microsoft.com/en-in/cc678047(en-us).aspx (Operating System Deployment with System Center Configuration Manager 2007 )
http://technet.microsoft.com/en-in/cc677236(en-us).aspx ((Deploying System Center Configuration Manager 2007 )