View Full Version : Alternator Upgrade

03-22-2008, 08:48 AM
Looking for a high amperage alternator.Something over 100 amps to 140 amps.
Anyone know of any that bolt onto 67 B Body, big block

03-22-2008, 09:25 AM
An OE unit from the later 70's can be had at this power level but might take a bit of thinking to get it just right or use a bracket from said year car. Like a '78 bracket.

Alignment could an issue if you start useing different year brackets.

The Alt. would need longer wires on a stock bracket.

The AMP gauge should be disconected for saftey.

03-22-2008, 12:36 PM
The 70's hi-output unit could be used along with the correct brackets, but these are very bulky & heavy, also the correct brackets may be difficult to find. I would check out either Bouchillon Performance or Mancini Racing for the late model retrofit alt/bracket kit. Wiring for these hi-output alternators will need to be improved over the stock wiring as well unless you want a BBQ under the hood. Bypassing the factory amp gauge is a good idea since the full current of the charging system is routed thru it and the ammeter is prone to failure. To accomplish this, disconnect the black wire from the back of the alt, and install another 10gauge wire with an inline 14gauge fusible link to the stud on the starter relay. You will need to install an aftermarket voltage gauge if doing this.

03-22-2008, 12:41 PM
If you put 100 plus amps to old 1967 wiring you will probably end up with a fire. Just my opinion, cause i'v seen it happen.

03-22-2008, 05:24 PM
Not if you know what you are doing...

There is an article in the performance talk archives (http://www.moparchat.com/forums/showthread.php?t=61642), about upgrading to an newer ND alt from a Ram or a Jeep. I got my alt on ebay a couple of years ago. You need to get a GM pulley for the alt and then grind down the inside lip. Then the pulley will bolt right on to the ND alt.

You will need to run a heavier gauge wire from the alt to the batter. This will bypass the weak link (alt gauge). From the battery, you can connect a fused power distribution block. You feed all of your high current draw electronics at this point.

It would be best to upgrade the Regulator, if you haven't done so already. They make a solid state replacement that looks like the original.

03-22-2008, 07:06 PM
The original wiring CAN be used with the hi-amp alternator, however with the wiring being 40+ yrs old and the added output of these alternators I wouldnt suggest it from a reliability or safety standpoint. As I had mentioned above, the wiring from the output stud of the alternator should be replaced & upgraded with a length of 10gauge min. wire w/ a fuseable link to protect the rest of the harness & bulkhead connector. This wire that runs thru the bulkhead in most factory harnesses, with the exception of some fleet/police vehicles, is a major culprit in electrical problems in vintage Mopars. The factory realized this later on, as well & later routed this wire thru a separate grommet in the firewall. Melted bulkhead connectors/damaged wiring in this area is usually caused by the wire creating so much heat from either high resistance in old/corroded/poor cond. wiring, or a defective charging system. I've performed this modification on all of my Mopars & have had no further problems. Most newer repro wiring harnesses are also made of superior quality wiring to that of cars made 40 yrs ago as well. The time to perform this modification is 10 mins. & around $5. Either do it now, or take the chance of spending $200-800 for replacement harnesses. I'm sure that many people can attest to this very thing happening on their own cars, even with the low-amp orig. alternators that came on their cars originally.

03-22-2008, 08:30 PM
Thats what i am hearing from most.
I just wanted to be sure about running to the battery with the high amp. alt. wire.
My present wiring is working fine, but am pulling my motor to install a new one with much more power and also upgrading to a Wizard Radiator with 4 electric fans to cool the extra power.Plus going with an electric water pump.
It really doesn't mater to me what brand of alternator i use.I can make the brackets and install them with proper alinement.
I thank all who replied .
Has anyone done this before and if so what brand did they buy ?

03-22-2008, 10:13 PM
I'd advise thinking things through carefully. In all the Mopars of that era, and especially now that "we" and they are getting old, there are several weak links. One is the firewall connector, and the main, heavy power goes through there at least twice. This is joined by the fact that the wiring itself in the heavy charging and ammeter circuit is too small for really heavy loads

The second is the ammeter itself. Many of the dash designs are imbedded in plastic, so that if the heavy current through the meter warms up the connections, they actually get loose, and from there on in it snowballs. (or fireballs!!)

The ignition switch itself, can be a problem, along with it's connector, now that things are "old."

Even if you take the fan power out from a main battery connection, YOU STILL HAVE the heavy alternator charging current going through the forementioned.

I'm not sure what the best answer is-----

it depends on if you want to keep the vehicle absolutely stock, or are willing to modify a few things. I like ammeters, and so, instead of bypassing them like so many advocate, I'd rather parallel or replace the heavy wiring up into the dash with mush heavier. "Back in the day" I put #6 in my Roadrunner. I'm a radio amateur and have been since I was a kid, so my cars have at some time always had extra junk here and there.

03-23-2008, 09:04 AM
Mancini Racing (http://chucker54.stores.yahoo.net/delialbrpk.html) sells a kit that has a 120 amp lightweight Denso alternator and the brackets.

03-23-2008, 10:31 AM
Thanks Madmax for the heads up on the Denso alt. from Mancini's.
I ordered it this morning.

I've also contacted a wiring expert to make sure i get this thing in correctly.
I wouldn't want it to burn down on me.
Thanks to all who replied .It made me see that it needs to be done in the proper way so not to have any further problems/fires etc.
These forums really work well for info.
Have a great day.Mopar rules !

03-23-2008, 01:02 PM
Right on!

03-23-2008, 10:02 PM
Again, many are missing the solution that I stated and linked to.

For price and availability, the ND alt is a great choice.

For the wiring issue, you run a 6G parallel feed from the alt to the battery. This feed does not touch the bulkhead. It does not touch the alt gauge. You run another fuse box directly from the battery. This box feeds all of your high current add-ons. It is also a great box to feed a headlight wiring upgrade. This takes all high current feeds away from the bulkhead.

03-24-2008, 06:58 PM
I believe the kit Mancini racing sells is a ND alt. The single 10gauge wire w/ 14gauge fuse link from the alt output to starter relay stud does the same thing. Unless on a actual "resto" type show car, this is probably the best way to avoid bulkhead electrical problems. The factory ammeter on the instrument cluster is mechanical, much like the older style voltage regulator, and due to its inherent design & age, is prone to failure. Many circuit board failures as well as wiring harness damage can be attributed to this. The factory knew that, and thats why the design was later changed.