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

I'm going to have to agree with this, there is not enough time to split 1st and 2nd in my car, usually paddling the throttle to regain traction, 2nd to third not much time to make it worth splitting either, I was just mainly looking for an OD, that GM auto looks pretty bulky though, what mods do you have to make to the torsion bar crossmember?
I`m glad you posted on this, I`ve been wondering about the splitting thing--thanks.