727 Lower Gear Set for street/highway use

If I’m not mistaken, putting any kind of overdrive transmission or gear vendors unit on your 727 will require some modification to the floor to fit. From what I have gathered and heard of, the GV unit is relatively easy to make fit. Just need an air hammer to make a few dents in the floor. I built one for a guy couple years ago and he said it dropped his RPM significantly on the highway at 75mph. I can’t remember exact RPM drop but he drives the car from Butler, PA to Carlisle, PA which is about 3-3.5 hour trip in his car. So if you would ask him, he would say the GV is worth the investment.