OFFT: Help with RedHat 6.2 Xserver config

I just installed Red Hat 6.2, and seem not to be able to change display settings for the X server. What I have is 1280x1024 16bit, ??Hz vertical frequency, I set it up using Xconfigure. What I want is all that plus 75Hz exact vertical refresh rate. Otherwise, my display flickers heavily when I switch it between computers (I am using a switch). I think this is not the last topic I am going to suffer with. If anybody who is a linux expert and who is willing to answer a few newbie questions gets in touch with me directly, I'd appreciate it very much. TIA, Big K