I have a LS2 in a 89 firebird wanting to use the Holley standalone. I just do not even know where to start because I want to use stock gauges. I am very new to wiring and do not like it at all but I want it done right and correctly. If anyone has any picture of how they set up their wiring or any advice please let me know!
You are going to just have to install 2 different Sets of Instrument/ Gauge Sending-Units/ Sensors for each type (Coolant Temp, Oil Pressure, Etc.).
One set comes with the Harness for the LS2.
The others will be from the original Engine your Car.
There are Thread Adapters/ Sending-Unit Adapters for you to use (Metric to SAE).
Speedo will need an aftermarket VSS Box.
Tach can run off of the LS2 Ignition with a Tach Adapter.
Alternator connects to the Voltage Gauge like Factory.
You most likely need an inline Resistor.
The Image below is a Jumper Harness that Plugs into the Alternator with the needed Resistor Inside:
I also make these with an optional replaceable Resistor in an ATM-Fuse Socket, show below:
Lastly, I also make these for other GM Alternators, and make Adapter Jumper Harnesses as well, shown below:
