1966 Barracudas came with the same console they used in the 1967 and later A bodies. You would need the console, brackets and shifter handle. That is assuming that your shifter linkage accepts the same type of bolt on handle.
I had a buddy who installed a 4 speed overdrive in a column shift 67 Valiant. He had a reverse lever under the dash. Not sure how he rigged the linkage
I checked the website and it appears to be a stock rebuilt 4 speed overdrive. Check out the specs on their "hemi" 4 speed overdrive for the differences.
I spoke to him briefly at Carlisle. Pretty much the same response, waiting on final parts to come back from machining and will be building them very soon.