The "conversion" harness gets you the stub that would have been installed at the factory.
Once the conversion harness is there you use the console harness to connect that console gauge package to the conversion.
In my buddy's 69 RS the two harnesses had everything to connect the gauges except the oil pressure line. In fact he thought he would need the tach harness, but that was already included in the harness.
Great directions that came with the harnesses and the http://factoryfit.com
website had all the details on which console harness to get and why he needed the conversion.
You will need to swap out the temp idiot light switch from the block for the correct gauge sender unit, again wiring in the harness already. Think he had to order that gauge sender when he purchased the gauge cluster.
Fuel sender stays the same.
In 68 and 69 console gauge sets the Oil pressure switch gets ditched for the oil line. Make sure you get a quality line and has correct brass fittings otherwise oil will flow nicely into the cockpit or all over the back of the engine. I don't know if 67 is mechanical or electric but someone here will know and drop in.
Double check tach requirements and hookups if you have installed aftermarket ignition/distributor setup. Factory tach is not happy without special filters in those setups. Factory setup work like a champ out of the box using the harness instructions.
Ammeter will work on these harnesses, unless you purchased a volt meter conversion gauge. I know AAW / Factoryfit.com make one for the 68/69 "saw-tooth" style gauges - don't know about 67's gauges. for 68/69 there is a conversion harness included with the volt meter gauge. And they sell amp to volt conversion harnesses for aftermarket so cruise the website.
Was a fun project but took two days - could have been done in one - he had distractions left and right. Don't think a 67 would be much different.