SPECIMEN

                      CERTIFICATE GUARANTY INSURANCE POLICY


OBLIGATIONS:                                    $92,320,000
            POLICY NUMBER:
            Block Mortgage Finance
            Asset Backed Certificates, Series 1998-1
            Class A-6 Certificates

     MBIA Insurance Corporation (the "Insurer"), in consideration of the payment
of the premium and subject to the terms of this Certificate  Guaranty  Insurance
Policy (this "Policy"), hereby unconditionally and irrevocably guarantees to any
Owner that an amount  equal to each full and  complete  Insured  Payment will be
received by Bankers Trust Company of  California,  N.A., or its  successors,  as
trustee  for the  Owners  (the  "Trustee"),  on  behalf of the  Owners  from the
Insurer,  for  distribution  by the  Trustee  to  each  Owner  of  each  Owner's
proportionate share of the Insured Payment. The Insurer's  obligations hereunder
with respect to a particular  Insured  Payment shall be discharged to the extent
funds equal to the applicable  Insured  Payment are received by the Trustee from
the  Insurer,  whether or not such funds are  properly  applied by the  Trustee.
Insured Payments shall be made only at the time set forth in this Policy, and no
accelerated Insured Payments shall be made regardless of any acceleration of the
Obligations, unless such acceleration is at the sole option of the Insurer.

     Notwithstanding  the  foregoing  paragraph,  this  Policy  does  not  cover
shortfalls, if any, attributable to the liability of the Trust, any REMIC or the
Trustee for  withholding  taxes,  if any  (including  interest and  penalties in
respect of any such liability).

     The Insurer will pay any Insured Payment that is a Preference Amount on the
Business  Day  following  receipt  on a  Business  Day by the  Fiscal  Agent (as
described  below) of (i) a certified  copy of the order  requiring the return of
such Preference Amount,  (ii) an opinion of counsel  satisfactory to the Insurer
that such order is final and not subject to appeal,  (iii) an assignment in such
form as is  reasonably  required by the  Insurer,  irrevocably  assigning to the
Insurer  all  rights and claims of the Owner  relating  to or arising  under the
Obligations  against the debtor which made such preference  payment or otherwise
with respect to such  preference  payment and (iv)  appropriate  instruments  to
effect  the  appointment  of the  Insurer  as agent for such  Owner in any legal
proceeding related to such preference payment,  such instruments being in a form
satisfactory to the Insurer, provided that, if such documents are received after
12:00 noon,  New York City time, on such Business Day, they will be deemed to be
received on the following  Business Day. Such payments shall be disbursed to the
receiver  or  trustee  in  bankruptcy  named in the  final  order  of the  court
exercising  jurisdiction  on behalf  of the Owner and not to any Owner  directly
unless such Owner has returned  principal or interest paid on the Obligations to
such  receiver or trustee in  bankruptcy,  in which case such  payment  shall be
disbursed to such Owner.

     The Insurer will pay any other amount payable hereunder no later than 12:00
noon,  New York City time,  on the later of the  Distribution  Date on which the
related Insured  Payment is due or the second Business Day following  receipt in
New York,  New York on a Business  Day by State  Street Bank and Trust  Company,
N.A., as Fiscal Agent for the Insurer,  or any successor  fiscal agent appointed
by the Insurer (the "Fiscal Agent") of a Notice (as described  below),  provided
that, if such Notice is received  after 12:00 noon,  New York City time, on such
Business Day, it will be deemed to be received on the following Business Day. If
any  such  Notice  received  by the  Fiscal  Agent is not in  proper  form or is
otherwise  insufficient for the purpose of making claim  hereunder,  it shall be
deemed  not to have been  received  by the  Fiscal  Agent for  purposes  of this
paragraph,  and the  Insurer  or the  Fiscal  Agent,  as the case may be,  shall
promptly so advise the Trustee and the Trustee may submit an amended Notice.

     Insured Payments due hereunder,  unless  otherwise  stated herein,  will be
disbursed  by the  Fiscal  Agent to the  Trustee on behalf of the Owners by wire
transfer of  immediately  available  funds in the amount of the Insured  Payment
less, in respect of Insured Payments related to Preference  Amounts,  any amount
held by the  Trustee  for  the  payment  of such  Insured  Payment  and  legally
available therefor.

     The Fiscal  Agent is the agent of the Insurer  only,  and the Fiscal  Agent
shall in no event be liable to Owners  for any acts of the  Fiscal  Agent or any
failure of the Insurer to deposit, or cause to be deposited, sufficient funds to
make payments due under this Policy.

     As used herein, the following terms shall have the following meanings:

     "Agreement"  means the Pooling and Servicing  Agreement dated as of January
1, 1998 by and among Block Mortgage Finance, Inc., as Depositor, Block Financial
Corporation, as Master Servicer,  Companion Mortgage Corporation, as Seller, and
the Trustee,  as trustee,  without regard to any amendment or supplement thereto
unless such amendment or supplement has been approved in writing by the Insurer.

     "Business  Day" means any day other than a  Saturday,  a Sunday or a day on
which the  Insurer  or banking  institutions  in New York City or in the city in
which the  corporate  trust office of the Trustee under the Agreement is located
are authorized or obligated by law or executive order to close.

     "Insured  Payment":  means,  with respect to the Related Loan Group and any
Distribution Date, without  duplication,  (A) the excess, if any, of (i) the sum
of (a) the aggregate amount of interest accrued at the related Pass-Through Rate
during the preceding Accrual Period on the Class A Certificate Principal Balance
of the related Class A Certificates  (net of any Prepayment  Interest  Shortfall
and  the  interest  portion  of  reductions  due to the  Relief  Act),  (b)  the
Preference Amount as it relates to interest previously paid on each Class of the
related Class A Certificates prior to such Distribution Date, (c) the portion of
the Carry Forward  Amount  related to interest with respect to each Class of the
related Class A Certificates (net of any Prepayment  Interest  Shortfall and the
interest  portion of reductions due to the Relief Act) and (d) the then existing
Subordination  Deficit  for the  Related  Loan  Group,  if any,  over (ii) Total
Available Funds (net of the Insurance Premium Amount for the Related Loan Group)
after  taking into  account  any  Principal  Distribution  Amount to be actually
distributed on such Distribution Date and the cross-collateralization provisions
of the Trust  Fund  plus (B) an amount  equal to the  principal  portion  of the
Preference Amount with respect to the Related Loan Group.

     "Notice" means the telephonic or telegraphic notice,  promptly confirmed in
writing by telecopy  substantially in the form of Exhibit A attached hereto, the
original of which is  subsequently  delivered by registered  or certified  mail,
from the Trustee  specifying the Insured Payment which shall be due and owing on
the applicable Distribution Date.

     "Owner"  means  each  Owner  (as  defined  in the  Agreement)  who,  on the
applicable  Distribution  Date,  is entitled  under the terms of the  applicable
Obligations to payment thereunder.

     "Preference Amount" means any amount previously  distributed to an Owner on
the  Obligations  that is  recoverable  and sought to be recovered as a voidable
preference by a trustee in bankruptcy  pursuant to the United States  Bankruptcy
Code (11  U.S.C.),  as amended  from time to time,  in  accordance  with a final
nonappealable order of a court having competent jurisdiction.

     "Related Loan Group" means the Adjustable Rate Group.

     Capitalized  terms used herein and not otherwise  defined herein shall have
the  respective  meanings set forth in the Agreement as of the date of execution
of  this  Policy,  without  giving  effect  to any  subsequent  amendment  to or
modification  of the Agreement  unless such amendment or  modification  has been
approved in writing by the Insurer.

     Any notice  hereunder  or  service  of  process on the Fiscal  Agent of the
Insurer  may be made at the  address  listed  below for the Fiscal  Agent of the
Insurer or such other  address as the  Insurer  shall  specify in writing to the
Trustee.

     The notice  address of the Fiscal  Agent is 15th Floor,  61  Broadway,  New
York, New York 10006, Attention:  Municipal Registrar and Paying Agency, or such
other address as the Fiscal Agent shall specify to the Trustee in writing.

     This Policy is being  issued  under and pursuant to, and shall be construed
under, the laws of the State of New York,  without giving effect to the conflict
of laws principles thereof.

     The   insurance   provided   by  this   Policy  is  not   covered   by  the
Property/Casualty  Insurance  Security  Fund  specified in Article 76 of the New
York Insurance Law.

     This Policy is not cancelable for any reason. The premium on this Policy is
not refundable for any reason  including  payment,  or provision  being made for
payment, prior to maturity of the Obligations.






     IN WITNESS  WHEREOF,  the Insurer has caused this Policy to be executed and
attested this 28th day of January, 1998.

                           MBIA INSURANCE CORPORATION


                           By-------------------------------
                             President


Attest:                    By-------------------------------
                             Assistant Secretary







                                    EXHIBIT A
                    TO CERTIFICATE GUARANTY INSURANCE POLICY
                                  NUMBER 25622

                        NOTICE UNDER CERTIFICATE GUARANTY
                          INSURANCE POLICY NUMBER 25622


State Street Bank and Trust Company, N.A.,
  as Fiscal Agent for MBIA Insurance Corporation
15th Floor
61 Broadway
New York, NY  10006
Attention:  Municipal Registrar and Paying Agency

MBIA Insurance Corporation
113 King Street
Armonk, NY 10504

     The undersigned, a duly authorized officer of  ___________________________,
as trustee  (the  "Trustee"),  hereby  certifies  to State Street Bank and Trust
Company,   N.A.  (the  "Fiscal  Agent")  and  MBIA  Insurance  Corporation  (the
"Insurer"),  with reference to  Certificate  Guaranty  Insurance  Policy Number:
25622 (the  "Policy")  issued by the  Insurer  in respect of the Block  Mortgage
Finance Asset Backed  Certificates,  Series 1998-1,  Class A-6 Certificates (the
"Obligations"), that:

         (i)  the  Trustee  is the  trustee  under  the  Pooling  and  Servicing
     Agreement dated as of January 1, 1998 by and among Block Mortgage  Finance,
     Inc.,  as  Depositor,  Block  Financial  Corporation,  as Master  Servicer,
     Companion Mortgage Corporation,  as Seller, and the Trustee, as trustee for
     the Owners;

         (ii) the Class A-6 interest accrued at the Pass-Through Rate during the
     preceding Accrual Period (net of any Prepayment  Interest Shortfall and the
     interest  portion of reductions due to the Relief Act) for the Distribution
     Date occurring on ____________________ (the "Applicable Distribution Date")
     is $____________________ (the "Class A-6 Interest");

         (iii) the interest  portion of the  Preference  Amount related to Class
     A-6 for the Applicable Distribution Date is  $_________________(the  "Class
     A-6 Preference Interest");

         (iv) the portion of the Carry Forward  Amount  related to interest with
     respect  to Class A-6 (net of any  Prepayment  Interest  Shortfall  and the
     interest portion of reductions due to the Relief Act) (the "Class A-6 Carry
     Forward Amount") for the Applicable Distribution Date is $______________;

         (v) the  Subordination  Deficit for the Related Loan Group, if any, for
     the   Applicable   Distribution   Date   is   $____________________    (the
     "Subordination Deficit");

          (vi) the sum of the Class A-6  Interest in (ii),  the Class A-6 
     Preference Interest  in (iii),  the Class A-6 Carry  Forward  Amount in
     (iv),  and the Subordination  Deficit  in  (v)  is  $____________________
     (the  "Required Distribution");

          (vii) the amount of Total Available Funds for the Applicable
      Distribution Date is $______________________(the "Total Available Funds")

         (viii) the Required Distribution in (vi) minus Total Available Funds in
     (vii) is $________________;

         (ix) the principal portion any Preference Amount which is payable under
     the  Policy  and  not  heretofore   paid  is   $____________________   (the
     "Applicable Principal Preference Amount");

         (x) the sum of the  amount  set  forth  in (vii)  plus  the  Applicable
     Principal Preference Amount in (ix) is $____________________ (the "Insured
     Payment");

         (xi) the Trustee is making a claim  under and  pursuant to the terms of
     the Policy for the dollar  amount of the  Insured  Payment set forth in (x)
     above to be applied to the  payment of the  Required  Distribution  for the
     Applicable  Distribution  Date in accordance with the Agreement and for the
     dollar  amount of the Insured  Payment set forth in (x) above to be applied
     to the payment of any Preference Amount; and

         (xii) the Trustee  directs that payment of the Insured  Payment be made
     to the  following  account  by bank  wire  transfer  of  federal  or  other
     immediately  available  funds in  accordance  with the terms of the Policy:
     [TRUSTEE'S ACCOUNT].

     Any Person Who Knowingly  And With Intent to Defraud Any Insurance  Company
     Or Other Person Files An  Application  For  Insurance Or Statement Of Claim
     Containing Any Materially False Information, Or Conceals For The Purpose Of
     Misleading,  Information  Concerning Any Fact material  Thereto,  Commits A
     Fraudulent  Insurance Act, Which Is A Crime, And Shall Also Be Subject To A
     Civil Penalty Not To Exceed Five  Thousand  Dollars And The Stated Value Of
     The Claim for Each Such Violation.

     Any capitalized  term used in this Notice and not otherwise  defined herein
shall have the meaning assigned thereto in the Policy.

     IN WITNESS  WHEREOF,  the Trustee has  executed and  delivered  this Notice
under the Policy as of the ____ day of ____________, ____.



                                              , as Trustee


                                      By_______________________________________
                                      Title____________________________________