Need help with tach

I just purchased a 73 Mach 1 to drive around while I work on another 73 project Mach. A previous owner added a sunpro tach and mounted it to the steering column with a clamp and I hate how it looks. I also have a two complete dash gauges that have the factory tach in them. What can I do to get the factory tach to work with the wiring that was already done for the existing sunpro? Would I better off sending the tach to rcci? I really dont want to pull the whole harness as it is in great shape and at least the previous owner did a decent job of splicing into the harness without hacking it all up. Any help would be appreciated. Thanks.

Ron

Factory tach is "current sensing two wire" vs "voltage sensing three wire" for modern aftermarket tachs. The aftermarket wiring won't help with a factory tach. IIRC it is sort of a plug and play to add the factory tach to a stock car. I'm sure others here will have details.

All of the wiring harnesses forward of the tail-light must change with the dash cluster to be compatible with the OEM tach dash and elimination of the alternator indicator lamp. Sorry, but this is not a simple exchange. RCCI's solution for installing an aftermarket tach in a standard dash cluster Mustang is the cheapest and most elegant solution. Next in line is my refurbishment/conversion to tach, and third in line is aftermarket wiring kits and/or reproduction harnesses.

Go with the RCCI solution. It´s easy and it looks (and works) terriffic.

Thanks for all of the responses.