Alternators usually have their own built-in voltage regulator, at least the Delco 10-SI that's the most popular swap does. That eliminates the need for a firewall-mounted regulator, although some folks use a shelled-out regulator housing simply for the original appearance, with wiring routed through the empty case. That's also a handy place to put an auxiliary fuse panel, with the accessory wires hidden behind the dummy regulator.
The generator is a "dumb" unit- - - -it's either on or off, with no way to change its output other than with the remotely-mounted regulator. That unit controls voltage and current, and also disconnects the generator from the battery anytime generator voltage is lower than the battery to prevent the battery from discharging itself through the generator when the engine stops. All these functions can be adjusted by someone who knows what he's doing and who has the right test equipment, mostly by changing the spring tension on the vibrating points. It's very important to have a good ground wire running between the regulator base and the generator housing.
A generator running at full output with no control of the field coil circuit can destroy itself with overcurrent when charging a very low battery, or it can destroy a fully-charged battery with over-voltage. Maximum current and voltage output is controlled by the regulator inserting resistance into the field coil ground several times a second as the points vibrate. The generator/battery connection is made and broken by a relay directly behind the BAT wire of the regulator that's either open or closed- - - -it's not supposed to vibrate. Regulator points vibrate with a slight wiping action to self-clean, so never use anything abrasive like a file or sandpaper to clean them- - - -the scratches will make the points stick. I use a piece of business card or a thin strip of heavy paper cut from an index card if it's necessary to burnish the points inside a regulator.
Jerry
