this is a c.a.t. sfi approved balancer that was bolted to my 91 gt. i put a dss 306 motor, and found out the balancer i had for for an early model 302, 28oz balanced. you can go to their website (c.a.t. performace) to view specs. the part# is hbf-302 (a236254). best offer. it is new, just a few scratches from install and removal.