Hey David,
First of all does your alternator have internal voltage regulator?
Most do, and you will not need eternal voltage regulator! Keep us posted!
Richard D. Hord
P.S. Here is my old post about conversion!
Generator to Alternator conversion
Houston we have power!
Boy it was a booger. I'm going to try to explain what I done to complete this project. Special thanks to Ray Clark for all his information and his input.
I tried to contact C.R.A.P. for bracket and never got a response. So I used what I had and it don't look bad at all. And best of all it works!!!
Disconnect and remove battery!
First you want to purchase one wire GM Del-co alternator with internal regulator and pulley. Remove old generator.
Measure from the radiator (the radiator is a stationary point of reference) to get you a dimension to the center line of the crank pulley and the fan pulley, (this dimension should be the same) write this dimension down. The alternator pulley needs to be the same dimension.
If your bracket is like mine it was all one piece, You got the front part that mounts to the water pump, a cross piece that ties to the rear part that bolts to the block.
Take a reciprocating saw and cut cross piece out, close to the back part and close to the front part.
Measure from the radiator back to front part of bracket, write that dimension down.
With pulley on new alternator hold rule, center line of pulley, on dimension you got on fan pulley and crank pulley center line (should be same) see how much you need to get to the front of mounting position on new alternator. EXAMPLE: mine was 3/4"
Remove fan and fan pulley from engine. Remove front part of alternator bracket. Remove upper stud, it will come out with vise grips and twist.
Now you need to make a list of things you need. I needed 12" 7/16" all-thread rod, two lock washers, two nuts, 2" x 3/8" bolt, 3" x 3/8" bolt, 6" x 1/2" ID galvanized pipe, 4" x 1/2" ID galvanize pipe, 3' number 8 wire, wire-end terminals and metric bolt and lock washer to fit Alternator hole for adjustment mounting bracket.
With the extra dimension you need to get front bracket out to be in line with outer pulleys, cut you two pieces off the 4" x 1/2" galvanized pipe (this is best done in vise)
Next is for the replacement for the stud you removed from the water pump. Take the 4" x 3/8" bolt and cut off threads and cut it long enough to accept the top part of front bracket plus shim, drive it into place where stud was and install galvanized pipe shim.
With the pieces of pipe you cut, shim out the front part of the bracket (stud and bolt) Attach front bracket to water pump. Use the 2" x 3/8" bolt.
Now measure from the front bracket to the rear bracket and deduct the Alternator mounting position. (Mine was minus two inches) this will give you the dimension you need to cut the 6" piece of pipe. Cut 6" pipe to that dimension.
Next measure from front bracket to back bracket and add enough to that dimension to except two lock washers, two washers and two nuts. Cut your all-thread rod to that dimension.
Remove tension bracket (mine had two bends in it) get bracket on solid surface and straighten bends with hammer (it needs to be straight) after you have done this reinstall.
Use your all-thread rod, put washer, lock washer and nut on one end. Start this into rear bracket and install pipe you have cut as shim. Work alternator into place and slide all-thread rod threw front bracket. Now install washer, lock washer and nut (hand tighten only) Bracket will be on front of alternator.
Now that alternator is hanging, jack up car set car jack stand in place and get under it. Align lower bracket and install metric bolt and lock nut (hand tighten only) Bracket will be on front of alternator.
Reinstall fan pulley and fan. Install belt. Tighten tension on belt, tighten tension nut and nuts on all-thread rod.
Take ARM wire (yellow wire that was attached to generator) and attach it and new number 8 wire with wire end connector to back of alternator. Tape up other two wires as they are not needed.
Attach other end of new number 8 wire with wire end terminal to battery side of solenoid. (where positive or red battery cable is connected)
Now to the voltage regulator. Gut it, disconnect any connections inside, and underneath, It is not needed, but I left mine because I wanted it to look original. Reinstall and hook it back up the way it was.
Arm post on voltage regulator you should have yellow heavy gauge wire and small yellow wire with black stripe. Go to wires on drivers side at firewall and look for small yellow wire with black stripe, cut it.
Reinstall battery.
Start car and check on fire wall for 12 volts, (I found this at relay in front of passenger) turn car off check for voltage again at that location, if it is dead attach wire then run to yellow wire with black stripe coming through firewall. Tape off other wire coming from Voltage regulator.
Start car and check voltage at ARM and BAT at voltage regulator, you should have 12 volts or a little more. (I had 13volts)
You should now have power and GEN light should go out when car is running.

Dave, I'm all about converting to an alternator. I did it on both of my classic Fords.

But, I have a question: If you're going to do the conversion, why didn't you go with a higher capacity alternator?

Newer Ford alt's put out 130-amps (or more), perfect for an electric fan, and they contain a regulator inside the alt. They're also smaller than the original generator. Bone yards have lots of them from Mustangs, Crown Vic's, trucks, etc. (They're cheap and only have two wires (POWER-to your battery, and GEN LIGHT-to sense the key is on.)

Sorry guys, but I absolutely hate the 1-wire alternators because they don't work the way you would expect they should. Get a Ford alt.

Your alternator probably puts out about 40-amps. Here's your hookup:

Alternator replacement wiring

Well I made a wiring harness as per your schmatic shows thank you simplyconnected the car finally is charging at 14.3v as it should. Did I ever have it wrong (6years). Now I have lost my gen light on the dash went and purchased new bulbs (57) and still I don't have a gen light. I hooked up the small yellow/blk stripe as described in the wiring schmatic is it possiable its is a fuse or the light switch? also please note everything is grounded and grounded again.

David

Replacing Generator with Alternator needing wiring instructions

The schematic I have on the 2G and 3G alternators shows a 510 Ohm resistor across the Gen light and a 20A fuse in place also. It also shows that lead coming from the Voltage Regulator goes to the Ign contact on the key switch. Other schematics show the resistor going to the ACC contact. I know this is doable because mine is working and others on here have made it work also. Here are some schematics that I have. Dave can get this sorted out for you, I am sure. The last two schematics are for later Buicks, so I do not know if they apply here.

You're the MAN! It tickles me when you guys troubleshoot and fix your problems using sound troubleshooting techniques. They work.

Your GEN light is fed from both ends with +12. The key switch feeds it, and so does a running generator OR alternator. (That's what turns it off.)

Some folks call it a 'TEST' light, because it shines when the key is on but the engine is not yet running. Originally (during generator days) it was connected to the armature (A - on the regulator), automatically polarizing it with a small current from the bulb. This is important because if the bulb is burned out, a generator may not charge.

The deal is, there is a relationship between the battery, the armature, and the bulb. The bulb only shines when the armature is putting out less voltage than the battery has.

Bulb shines when you:
Throw a belt, and the gen puts out less than the battery voltage;
Turn the key from OFF to ON, and the gen puts out less than the battery voltage.

Alternators God love them... They're always connected to the battery and depend on good diodes or they would drain the batt in no time. Alternators don't know when the key is on, so they use a 'SENSE' wire. Yep, you guessed it... the GEN light wire is tied to the key switch. So, how much voltage should the alt put out? The 'sense' wire tells the voltage regulator how much voltage is on the key switch, and the alt will produce power until 13.5-VDC is sensed on that wire.

CAUTION: If you have weak or loose wires feeding your dash, the alternator could produce more than the battery will take. Good grounds are JUST as important.

Dave, troubleshoot your GEN light from the yellow/blk wire. If you ground the wire (with the key on but the engine stopped) the light should shine.

If it doesn't shine, your troubles are from the key switch to the light socket, through the bulb, and out the firewall. The bulb is NOT grounded to the dash.

If it does shine when grounded, the problem is in the regulator connection (be sure the regulator has a good ground).

Follow this instruction and let me know what you found. Adding a 'shunt' resistor around the GEN light will make the bulb even dimmer, so tackle that later. - Dave

EDIT: There are no fuses on your ignition circuit. A yellow wire comes from your starter solenoid (+B), connects to your headlight switch (B), and jumps over to your key switch (B). From the key switch (IGN), a black/green wire feeds your bulb. The other bulb wire (yellow/black) continues through the firewall, to your voltage regulator.

Replacing Alt from Gen

Grounded the generator wire y/blk stripe from the gen light it doesn't light the bulb. I will check the ign and the light switch this week. the charging circuit is now charging great at 13.4v. again thanks for all the help. I used the schmatic that simply connected offered and made a colorcoded harness that looks good as an original harness.

David

Great! Now you know the problem isn't at the alternator or the voltage regulator. Re-check your light bulb. A GE-57 should work just fine:
It's a 14-volt, and around 1/3-amp. You really do need this bulb to work properly.