What is the best way to get an overdrive auto in a 67 Barracuda?

Good luck on being able to shift a gear vendors to split gears with any efficiency. I drove Mr Angry's Black '68 Charger with a 727 and a gear vendors. The thing was ok to shift into overdrive once in 3rd, but my hat is off to anyone who could effectively split 1, 2 & 3 on a drag strip or even in a street race. There's no way the average guy could master that to make it worth doing in a race. There may be guys out there, but it is very distracting with a throttle wide open.