Originally Posted by kleen56
I'm currently running a jumper wire from terminal #2 to the Batt post on the back of the alternator. If I run a wire from Terminal 2 to the battery direct, will that cause the alternator to energize quicker?
No. The #2 terminal is the sense terminal that allows the regulator to sense voltage in the system and adjust accordingly. While it works when simply run to the BATT post on the alternator (I have one set up this way), the regulator will be more accurate if the wire is connected further down the line, like at a junction block.
The energize signal comes from the #1 terminal. This needs to be connected to a switched 12V source through a small resistor (approx 35 ohms or so). GM did it either through the GEN light (using the filament resistance) or through an in-line resistor when the vehicle had a VOLT gauge instead of a light. The harness you noted simply has the resistor built in.
To answer your other questions, yes you can swap the pulleys on the newer alternators, and there's even a CS130 that bolts in place of the SI family (be sure to measure the spacing between the mounting lugs). Of course "newer" doesn't necessarily mean "better" - otherwise everyone here would be driving new cars powered by LS motors.
The CS130 and the like all work exactly the same as the SI family. They replaced the SI mainly because they are smaller and lighter - important for automakers trying to meet CAFE requirements but not necessarily better for a hotrodder. Ever priced rebuild parts for a CS alternator as compared to those for an SI?