Question: Replacing alternator

[Lib]

74 Big Block. Need to replace alternator, and am considering the 100 amp unit that is available, in lieu of the stock 63 amp. My only question: is that difference in output capacity significant enough to warrant any wiring upgrades to handle added charging load?

 

[Hib Halverson]

It is possible you have the car's electrical load and the maximum alternator output confused.

The alternator, regardless of its rated max. output, only generates enough current to satisfy the car's electrical load.

Unless you've modified the car's electrical system such that you need an additional 40-amps of current flow--examples would be high-wattage headlights, powerful high-end audio equipment, racing ignition system (such as MSD 7), aftermarket air conditioning or you tow a trailer--it is unlikely that you need a 100 amp alternator.

If you have modified the car's electrical system draw such that it's demanding 60-80 amps and you need that 100-am alternator, then you need to use 8-ga wire from the alternator to the battery.

 

[Lib]

Thanks Hib!!

 

[Hib Halverson]

Thanks Hib!!

You're welcome.
Glad to be of service.

FYI, the alt. I have on my 71 is a later model CS130. I installed it because the car has a more powerful stereo, MSD ign and quartz-halogen headlights.