First Trust Advisors L.P. 1001 Warrenville Road Lisle, Illinois 60532 May 25, 1999 Nike Securities L.P. 1001 Warrenville Road Lisle, IL 60532 Re: FT 320 Gentlemen: We have examined the Registration Statement File No. 333-69561 for the above captioned fund. We hereby consent to the use in the Registration Statement of the references to First Trust Advisors L.P. as evaluator. You are hereby authorized to file a copy of this letter with the Securities and Exchange Commission. Sincerely, First Trust Advisors L.P. Robert M. Porcellino Senior Vice President