Gauges on 73

I guess since I finally have some time I'll probably have more questions. I was thinking about fabricating a new dash with new dash components. If I bought the painless wiring harness for a 1973 CJ-5 would it still work for the new gauges? I was also thinking about adding some more components since I will be building the dash and wondering if this harness would have any drawbacks with some extra components (heater, switch for extra lights, etc.) By the way...Where the gauges on the 73 CJ5 Backlit??? I looked at a couple replacement gauges and they all listed lights. I have never had lights on my dash. I use a flashlight when driving at night to check speed.

 

Yes, '73 gauges were lit. The speedometer cluster was lit too. The dash controls and heater controls all have lighted labels.