Correct me if I am wrong, but I think E-bodies didn't have a fast ratio box. The AARs and TAs had longer pitman arms to effectively make them fast ratio.. You can buy those at PST. Rod
I have this option on build sheet. Also I saw a bulletin that they were standard on AAR and TA but added to 71 cuda with the 340 engine. I could be wrong on this. Is this only a longer arm? thought it was the whole box and arm. thanks, Bill