First of all, go here Mad Electrical
for alot of usefull information that you will need.
I just did this swap about a month ago. I have a '66 El Camino and it had an external voltage regulator. My problem was the GEN light came on one day. Ok, no big deal, I take out the alternator and voltage regulator to have them tested. Alternator comes back good, VR does not. I buy a new VR, install it and the light is still on. Long story short, the alternator was bad and the people at Autozone said it was good. It took a few trips and a few days of cussing and such until I was told about the MAD site. There is a whole lot of good info there, if you have the time, go through all of the tech articles. I also bought his "full power" set up, but ended up just buying a new foward lamp harness from M & H Electric Fabricators
which I highly recommend. I also had M & H do the internal regulator mod to the harness. That guy at MAD has very nice quality stuff, I just decided to go a different route after I bought it. I still might install the relays for the headlights one day.
Here is the skinny of what I did:
-Changed out my externally regulated VR for an internally regulated alternator. The alternator is a 12SI, 94 amp, at 3:00 (AC-DELCO # 321-266, Lester #7294-3 which is out of a 1984 Chevy Camaro, with 5.0L (305G) engine. The clock position varies from car to car.
-Ordered a new foward lamp harness from M & H with the 2 wire plug mod (internal VR) done to it. It's an additional $15.00 for the mod I believe.
Hope that help! Like I said, if you have the time go through all of those tech articles. Very good reading!
Here is a way to do it without a new foward lamp harness as it was explained to me. You need to buy a two wire plug for the new alternator which is sold at any parts store. OPG sells a conversion plug if you want it. The plug I am talking about is the one towards the top of the pic. The lower plug should just slide into the excisting plug at the alternator.
1. Splice the white wire (at the alternator) in your harness to the white wire on the new plug
2. Put a ring terminal on the red wire (on the new plug)(blue wire on the OPG kit) and run it to the post on the back of the alternator, along with the original 10 gauge red battery wire .
3. On the drivers side where the voltage regulator is splice (or make a jumper) the white wire and the brown wire...do not hook back up to the regulator, you can remove it if you like.
4. Presto, you're a chargin, and your original dash light will still work.
5. These alternators max charge at about 3000rpm, where as the original style won't max until near 5000. Oh, as a side benefit your headlights won't flicker anymore.