Duncan Motor sports ratchet shifter ?

I took a look at the www.duncan-motor-sports.com website and they sell a plate that replaces the stock gate on the old non ratcheting shifters, converting it to a ratchet shifter. Looks like its a snap to install. Anyone have experience with one of these ? Comments ?

I have a ratchet shifter from a '75 coronet I was considering using to replace the one in my 66 dart - anyone ever tried this ??