I want to pull my entire engine wire harness just the stuff that controls the engine; to intall my Haltech E6K.

I would still like to have all my stock indications in the intrument cluster. what wires are connected to the engine ECU that is connected to the instrument system? For example; what wire is use for RPM indication?

 

maybe its the one on the alternator or the crank sensors?

you really need to be asking on the ecu forum or the single turbo forum. There is a section specifically for your ecu although there may not be a quick reply you should get a correct answer.