BHJ Harmonic dampers offer the most precise and advance execution of the proven elastomer design. Most engine designers prefer alastomer-type dampers because of the durability, their superior high-frequency damping qualities and their ability to dampen all types of vibrations. These SFI approved dampers are all-steel, one piece and are lighter than the OEM units they replace. They have proven their merit in thousands of applications including off shore boats, Grand National stock cars, short track Super Modifieds, Pro Stock and other drap racing cars, Indy cars and street driven grocery getters. All critical OEM mounting dimensions are duplicated for accurate alignment of accessory drives. These balancers feature a TDC mark and are degreed from 0 to 50 degrees in 2-degree increments for accurate ignition timing. 90 degree marks are also included for easy valve adjustment.This special SFI approved balancer are recommended for those engines running over 6500 rpm. Installation instructions are included. This balancer is for the 1994-95 Ford Thunderbird Super Coupe and other applications for a 4.2L engine. These balancers must have zero balanced pulleys. If you have any doubt whether your pulley is balanced, take it to a machine shop and find out. Go with the side of caution.Free new bolt and washer comes with this unit.