I installed the powermaster 140amp. It fits the stock mount with no modifications (if it's a fox body 5.0). The one wire from the alternator to the positive side of the battery was all I needed, and it is supplied, as are the connectors, with the alternator. I taped up the original alt plugs with electrical tape and tied them neatly out of the way. This installation will not affect the stock voltmeter, as it is not tied into the alternator circuit. Very easy, and it solved my u/d pulley charging problems. My alternator excites at "startup high rpm", so I didn't need the extra wires and charges at idle.
I had one, but i didnt really like it. YOu had to be higher in RPMS as opposed to the 3G to get a decent charge. Also, in the kit, they gave me a 6 or 8 guage wire. So i had to go buy a 4guage wire also.
I have the 140 volt, the install is easy, use the stock bracket but I did have to grind a little off the bracket. It has a one wire hook up but I didn't hook it to the battery I hooked it to the bolt that the positive battery cable is hooked to.