There are many threads on this forum about 3G alternators. First, you will want to get a "small" body 3G alternator. Most of these will come with a serpentine pulley. However, Ford did put 3G alternators on some trucks and vans with v-belts. Here is one of those alternators on eBay: Alternator For Ford B600 B700 B800 Heavy Duty Bus 1990-1999 Alt-1807; AFD0025 | eBay

I installed one of these models of 3G alternators on my '68. Even though the alternator has a 2 belt pulley, my car only has one belt available for the alternator so I'm only using one belt to drive the alternator. Regarding the voltage regulator, the 3G alternators use an internal voltage regulator. On my car, I unwrapped the wiring loom running to the external voltage regulator and removed all the wires going to it and removed the voltage regulator from my car. I bought a 3G harness kit and wired it in and wrapped the loom back up. Ford Alternator Wire Harness Connector ASI 2G 3G 4G with 3G Stator Lead | eBay

Here's a wiring diagram:

There are other ways to convert to a 3G alternator. This is just the way I did it.

 

Easiest is 95A 3G for a '95-97 F-350 7.5L GAS engine. Small case, clocked correctly. Just need to swap pulleys.

 

Just curious if you've done this specific swap, because I just bought one and it has 8.25" spacing, is bigger than my stocker, not clocked correctly, and the lower bolt hole is too small.

 

The alternator I used does not need a pulley swap. I don't remember if I had to reclock it to have the connector point in the right direction; however, if I did the good thing is you don't need extra parts.

 

www.paperformance.com has the correct 95A 3G with a single sheave pulley installed.

 

www.paperformance.com has the correct 95A 3G with a single sheave pulley installed.

At double the price.

 

This is what I did:

How-to Install a High-Output Ford 3G Alternator into Older Fords

A Ford 3G integrally regulated alternator is the best choice for replacing old 1G externally regulated alternators on amped-up muscle cars.

www.motortrend.com

Ordered an ASI plug off EBay…did not reuse an old harness. used mega fuse and power cable from American Auto Wire. The last picture in article is the parts list, I used that Alternator.

 

One-wire alternators are the worst alternator type you can get. Their only advantage is a one-wire hookup. I always recommend people this before upgrading alternators:

BillaVista.com-Alternator Bible Tech Article by BillaVista

Its always best to read up on exactly how alternators work and the advantages and disadvantages of each type. Spoiler: One wire alternators only have one advantage....one wire hookup. They should be a last resort, especially if you run a large cam.

 

THanks for this, along with the inputs from everyone else. I really appreciate.

'm happy to upgrade from the original one wire. For what I am trying to do to the car, A/C, EFI, pertronix ignition, electric Fans, modest stereo, what amp level am I searching for without going overboard? Summit Racing recommended 200 AMP minimum.

 

With the exception of the conversion kit surrounding the higher amp 3G alternator, are there any other risks the higher amperage poses to the electrical system I should be worried about? Do I need to do further changes downstream, like to the headlights, etc? I understand that my stock ammeter can be converted to a voltmeter - easy to do or someone has to do it professionaly?

 

The best way is the heavy gauge charging circuit coming back to a circuit breaker, then from the starter solenoid post to the battery. That keeps it from frying the rest of your harness.

 

Use a 4 gauge cable from the alternator to the starter solenoid. Get rid of the amp meter. A high amp alternator will not damage anything except the original wire from te alternator to the starter solenoid. The alternator will not "Push" increased amperage to your headlights, etc. It will only provide the amperage that the accessory requires to operate. If your wiring is up to par, you will not have a problem. If your wiring is hot to the touch, then you may need to replace it.

 

Also, my understanding is that the higher amp alternators will not generate maximum output unless it is called for. Usually, the alternator will be generating much less power since your car won't actually be consuming the max all of the time.

 

this article is what I used as a guide for alternator purchase…and install.

How-to Install a High-Output Ford 3G Alternator into Older Fords

A Ford 3G integrally regulated alternator is the best choice for replacing old 1G externally regulated alternators on amped-up muscle cars.

www.motortrend.com

 

I'm not sure what belt system you have now, but I don't think anyone has mentioned yet that an alternator over 95 amps will require dual v-belts or a serpentine belt to turn it, unless you want a squeaking belt. I know some people will say that they have run high amp alternators with a single v-belt, but it is not recommended. The serpentine system is expensive, and that means you have to ditch the mechanical fan and go with electric fans, and they pull at least another 20 amps.

 

You can run a mechanical fan with a serpentine belt system as long as you pick the correct fan for a reverse-rotation pump. You can also run a multi-ribbed STANDARD rotation system using a ribbed water pump and crank pulley.

 

I figured you'd remember the Beanie and Cecil cap. I don't actually remember having one of those, but I did have Daniel Boone's:

 

Just a thought since the 3G produces more amps at lesser speed and belt slippage is an issue with more than 95 AMPS, would the use of a larger HIPO 289 Pulley be a benefit?

 

That is exactly what I used with a 3G 130 amp. It has never slipped or squealed or had a problem charging.

 

I've wondered if using a white regulator in place of the grey would help with the squeal. The white has a delayed charging, maybe it'll act like a soft start. Never had to try it though, cos I'm using a serpentine belt.

 

I haven’t had problems with a single stock style belt, 71 302 w 3g alternator.

 

I have one for sale, including the Hot Rod Magazine article that explains the wiring and the clocking. You'll just have to swap your current pulley over. I also have the harness (with fusible link) from a new edge mustang. I wired this exact setup right to my starter solenoid and it has been working excellent! Message me if interested.

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I just use the one off a 1995 Mustang 5.0 for all my vintage needs. I have one on my 69 Mach 1 with a 428 in it and my 64 Falcon with a 302, so they fit and work well.

 

Ended up getting a ‘95 mustang 3g, and apparently the 95 mustang small tab hole isn’t threaded, so it requires a bolt and a nut which is basically impossible to tighten to while also tensioning the pulley. Also, the pulley mount is shorter, so a dual v-belt isn’t able to thread on fully. Any other suggestions?

 

I have one of those, I drilled it out and used a Helicoil thread insert. I think I used a 3/8" bolt

 

I replaced the stock 60ish amp rebuilt alternator on my car with a black cases/fan/pullley, 125 amp Powermaster. My stock lower bracket was cracked so I found a black billet bracket from March with turnbuckle style belt tensioning which works fine with a single V belt and doesn’t squeal.

 

Soooo, I just bought a 95 amp 3G to replace the one-wire GM alternator that I’ve run for years. It may or may not solve my electrical problems, we’ll see.

This GM alternator has caused problems forever.
When not running the damn thing kills my battery, so I end up disconnecting the trunk-mounted battery ground when I’m not driving the car. With the ground unhooked and a multimeter completing the ground circuit, it’s pulling the full 13 volts. Unhook the alternator, and the meter pulls zero.

I vaguely recall having to make some wiring harness changes behind the instrument cluster. IIRC it had something to do with getting my external battery cutoff switch to function correctly for NHRA tech. When they throw the switch, the motor has to quit immediately. Before making those harness changes, the motor would continue to run for a few seconds (spinning alt still making volts) and that’s a no-go for tech.

Getting my instrument cluster out is a bit of a pain in the ass. Column mounted tach on the left side, shift light on the right side. I kinda hope I don’t have to pull the cluster. But if so, so be it.

 

Soooo, I just bought a 95 amp 3G to replace the one-wire GM alternator that I’ve run for years. It may or may not solve my electrical problems, we’ll see.

This GM alternator has caused problems forever.
When not running the damn thing kills my battery, so I end up disconnecting the trunk-mounted battery ground when I’m not driving the car. With the ground unhooked and a multimeter completing the ground circuit, it’s pulling the full 13 volts. Unhook the alternator, and the meter pulls zero.

I vaguely recall having to make some wiring harness changes behind the instrument cluster. IIRC it had something to do with getting my external battery cutoff switch to function correctly for NHRA tech. When they throw the switch, the motor has to quit immediately. Before making those harness changes, the motor would continue to run for a few seconds (spinning alt still making volts) and that’s a no-go for tech.

Getting my instrument cluster out is a bit of a pain in the ass. Column mounted tach on the left side, shift light on the right side. I kinda hope I don’t have to pull the cluster. But if so, so be it.

So, an update on this^
95 amp 3G Aerostar alternator is slicker than snot😜
I clocked it so the connectors are facing down and I spent some time making a tidy wiring harness, so the instal is very clean.
I should’ve done this years ago 👍

 

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