OLDWICK, N.J.–(BUSINESS WIRE)– #insurance–AM Best has assigned a Performance Assessment (assessment) of PA-2 (Excellent) to Gridiron Insurance Underwriters, Inc. (Gridiron) (Plantation, FL) and Signature Specialty, LP (Signature) (Plantation, FL). Signature is a wholly owned subsidiary of Gridiron. The outlook assigned to the assessment is stable.The assessment reflects Gridiron’s exceptional underwriting capabilities, excellent governance and internal controls, strong financial condition, excellent organ