[Ironhorse]

Just because the shift indicator shows GR (grade retard) would not rule out the trans has been changed to a Powerglide. My BIL has a 57 wagon that shows GR on the dash, thought that was what he had until seen Powerglide cast into the side of the trans. The Turbo Hydramatics were really dogs from what I understand and gave problems from day one. Think I would look for a newer aluminum PG for almost a direct swap or maybe even go to a TH350 or the overdrive 700R4. Would require a bit of mod work but would be a better choice in my opinion. Good luck in your choices.