Dual Weber Intake, auto Tran, cable conversion?

Not sure where to start. Ok I've got a 66' 270 with and Automatic Transmission, Just rebuilt the 225 with a Clifford Performance Rebuild, and the Dual Weber 38' intake, and headers. Having trouble converting the Rod style throttle to a cable. The peddle sticks/hangs up, if I push down too hard on it sometimes it will pop off the old rod inside. Also I don't believe I'm getting a full peddle range. Any ideas what I can Do.