Having extra amps available won't force your car to draw them. But, if your car does draw them, you might put too much through the charge wire (which runs from the alternator to the starter motor, where the battery cable connects). I recently replaced my alternator with a 100-amp unit (although I used a more modern GM alternator, rather than an aftermarket unit), so I "piggybacked" a 10-gauge wire in addition to the existing charge wire. It's a simple matter of following the existing wiring harness, and crimping a couple ring terminals on the ends of the wire (3/8" for the starter end - the other end will vary depending on the amternator that you use).
I would also suggest that you use the starter terminal as your power distribution point. In other words, if you want to add some extra electrical accessories (amplifiers, or whatnot), you should get an "auxilliary fuse panel" (NAPA sells them), mount it somewhere that is protected from the elements, but accessible, and then run another wire (12-gauge is fine, but you could use 10-gauge if you bought a big spool for the charge lead and have enough left over) from it's primary power terminal, out to the starter terminal. This way, it is able to draw directly from the new charge lead that you installed.
Joe
