Wow! I didn't even know about those things. So cool.Dad's Galaxie has a GearVendor's behind the Top loader. It makes the car. The GearVendors has a .78 overdrive ratio compared to the .75 of the 4L80E, an imperceptible difference. The GearVendors unit is a little girthy. It was very tight in Dad's car. We had to massage the tunnel.