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                                                                     EXHIBIT 8.1

                          [JENNER & BLOCK LETTERHEAD]

                                  June 24, 1999





General Dynamics
3190 Fairview Park Drive
Falls Church, Virginia 22041-4523

Gentlemen:

       We are acting as counsel to General Dynamics Corporation, a Delaware
corporation ("General Dynamics"), in connection with the proposed merger (the
"Merger") of Tara Acquisition Corporation, a Delaware corporation ("Merger
Sub"), a wholly-owned subsidiary of General Dynamics, with and into Gulfstream
Aerospace Corporation, a Delaware corporation ("Gulfstream"), with Gulfstream
surviving. The Merger will be consummated pursuant to an Agreement and Plan of
Merger, dated as of May 16, 1999, by and among Gulfstream, Merger Sub, and
General Dynamics (the "Merger Agreement").

       General Dynamics has filed with the Securities and Exchange Commission
under the Securities Act of 1933, as amended (the "1933 Act"), a registration
statement on Form S-4 (File No. 333-80213) (the "Registration Statement") with
respect to the common stock of General Dynamics to be issued to holders of
shares of common stock of Gulfstream pursuant to the Merger. In addition,
General Dynamics and Gulfstream have jointly prepared, and we have reviewed, a
Joint Proxy Statement/Prospectus which is contained in and made a part of the
Registration Statement (the "Joint Proxy Statement/Prospectus"), and the
Appendices thereto, including the Merger Agreement. In rendering the opinion set
forth below, we have relied upon the facts and assumptions stated in the Joint
Proxy Statement/Prospectus and upon such other documents as we have deemed
appropriate. Terms not otherwise defined herein shall have the meaning ascribed
to them in the Merger Agreement.

       We have assumed that all parties to the Merger Agreement have acted, and
will act, in accordance with the terms of the Merger Agreement and that the
Merger will be consummated at the Effective Time pursuant to the terms and
conditions set forth in the Merger Agreement without the waiver or modification
of any such terms and conditions. Under the Merger Agreement, it is a condition
to the closing of the Merger that General Dynamics and Gulfstream each receive
an opinion from their respective legal advisors to the effect that the Merger
will, based upon certain representations by General Dynamics and Gulfstream,
constitute a reorganization under Section 368(a) of the Internal Revenue Code of
1986, as amended.

       Based upon and subject to the foregoing, and subject to the
qualifications, limitations and assumptions contained in the portion of the
Joint Proxy Statement/Prospectus


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captioned "The Merger -- Federal Income Tax Consequences,"  to the extent the
statements contained therein relate to matters of United States federal income
tax law or legal conclusions with respect thereto, represents our opinion as to
the material U.S. federal income tax consequences of the Merger under
applicable law. No opinion is expressed on any matters other than those
specifically referred to herein.

       The opinion is furnished to you for use in connection with the
Registration Statement and may not be used for any other purpose without our
prior written consent. We hereby consent to the filing of this opinion as an
exhibit to the Registration Statement and to the references to this firm under
the caption "Federal Income Tax Consequences" in the Registration Statement. In
giving such consent, we do not thereby admit that we are in the category of
persons whose consent is required under Section 7 of the 1933 Act.


                                          Very truly yours,

                                          JENNER & BLOCK




