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

Reverse manual in mine as well. I'm running the shorty and I did have to massage my tunnel a bit. I would have gone with the longer version if i'd had known.
looks to e like the long version would have big effect on the pinion-driveshaft angle. anybody checked theirs / I ve got a 727 behind a 440/505, dana 60 in my 68fish, w/ 373 gears. would like to have a gear vendors, but the price is outa site !