I forgot to tell you that, the bulb was already burnt out. I am now suspecting a broken circuit inside the cluster. I am not sure but, I think it might be worth the risk to take the back housing off of the cluster around the rev counter gauge. I really don't know how to repair the circuit if it is indeed broken.
On top of that, I just put the speedometer cable back on and when I was driving the car around, I heard a hissing sound. I had forgotten to fasten on the vacuum line
Oh well, that goddamn thing can run a little rich until I come to a probable solution.
Please give any tips guys.