Assumed Characteristics of the Mortgage Loans Underlying the Group 1, 5, 6, 7, 8 and 9 Trust Assets¹: Principal Balance² Weighted Average Remaining Term to Maturity (in months) Weighted Average Loan Age (in months) Weighted Average Mortgage Rate³ Group 1 Trust Assets $300,000,000 357 2 6.3% Group 5 Trust Assets $  50,000,000 324 32 8.0% Group 6 Trust Assets $    5,773,162 146 205 10.0% Group 7 Trust Assets $229,300,000 357 2 5.8% Group 8 Trust Assets $  38,038,888 356 2 6.0% Group 9 Trust Assets $250,000,000 358 1 5.8% ¹As of June 1, 2003. ²Does not include Group 9 Trust Assets that will be added to pay the Trustee Fee. ³The Mortgage Loans underlying the Group 1, 7 and 9 Trust Assets may bear interest at rates ranging from 0.5% to 1.5% per annum above the related Certificate Rate. The actual remaining terms to maturity, loan ages and, in the case of the Group 1, 7 and 9 Trust Assets, Mortgage Rates of many of the Mortgage Loans underlying the Group 1, 5, 6, 7, 8 and 9 Trust Assets will differ from the weighted averages shown above, perhaps significantly. See "The Trust Assets – The Mortgage Loans" in this Supplement. See Exhibit A to this Supplement for certain  information  regarding  the  characteristics  of  the  Mortgage  Loans  included  in  the Underlying Trusts. Issuance of Securities: The Securities, other than the Residual Securities, will initially be issued in book-entry form through the book-entry system of the U.S. Federal Reserve Banks (the "Fedwire  Book-Entry  System").  The  Residual  Securities  will  be  issued  in  fully  registered, certificated form. See "Description of the Securities – Form of Securities" in this Supplement. Modification  and  Exchange:  If  you  own  exchangeable  Securities  you  will  be  able,  upon notice and payment of an exchange fee, to exchange them for a proportionate interest in the related Securities shown on Schedule I to this Supplement. See "Description of the Securi- ties – Modification and Exchange" in this Supplement. Increased Minimum Denomination Classes: Each Class that constitutes a  Principal Only, Non-Sticky  Jump,  Interest  Only   or   Inverse  Floating  Rate   Class.   See  "Description  of  the Securities – Form of Securities" in this Supplement. Interest Rates: The Interest Rates for the Fixed Rate Classes are shown on the inside cover page of this Supplement or on Schedule I to this Supplement. S-5