I am running a Mallory Unilight in my 1997 explorer 5.0. I ran it at first with only a coil, ballast resistor and the distributor. The Unilight can drive the coil without an ignition box and will perform flawlessley if you do not spike the electrical system(welding, jump start etc). I just added a Mallory Hyfire which helps burn off excess fuel(read less unburnt fuel and smell).
If you go with the standard Unilight setup without an ignition box it is a easy three wire hookup. Go here for instructions.
http://www.centuryperformance.com/Ma...eDist_RevH.pdf