I'm thinking about getting a Dakota Digital gauge cluster for my 1965 coupe with a c4 transmission. It has a speedometer cable right now, but the digital gauges requires installation of a vehicle speed sensor (VSS) in place of the speedo cable. Is this a relatively easy thing to do, or does it require taking apart the transmission? It looks like you just unscrew the cable and screw in the VSS, but there must be a catch..