You have to change the oil sender and the temp sender. The oil sender needs a line that will screw into the back of the gage. Temp sender is the one wire type. I did it but I'm still in the process of finishing it up.
I'm pretty sure you can still use the wires that go to the temp gage you just use one and make sure you hook the same one to the gage. Any auto place has the oil pressure sender. I used the copper type, seemed to work ok. Leaked alittle at first because I never tightened it up good enough.