I got a whole set of factory gauges out of a 78 truck. I have confirmed the gauges are from a 78 chevy truck ona couple different sights. The tach has a burned part on the board but I'm going to fix it. My question is how do I get the gauge cluster to work in my 74 chevy? Everything should work but oil pressure but I'm scared to hook it up because I don't know if there is anything different from the 74 gauge cluster. I don't have gauges on the left in my truck, I just have the four lights on the side. Let me know guys.