V8 Alternator Replacement Options

[Afireinside2285]

So will the 7294 or the 7278 bolt into the scout bracket and use the same plug? Just higher output?

Thanks

[BO185]

Originally Posted by Afireinside2285

So will the 7294 or the 7278 bolt into the scout bracket and use the same plug? Just higher output?

Thanks

Yes but you will need to add the shut wire to protect the ammeter wiring.

[Afireinside2285]

No problem with the shunt, Thanks

[RD Durham]

For vehicles I'd would add to Rbelflower any Chevy/GMC diesel truck. The early trucks had a 94amp 12si alternator as an option. The later trucks used CS alternators, usually CS130, and have the correct mounting brackets/arms. I would also add for SI alternators on Rbelflower's list to go back to late 1970's to 1985 for any of the cars listed. The higher end Chevy/GMC cars often had 15si or 17si alternators which would start at 105amps and go up to 120amps.

This is a link to an install I did on a diesel Scout II for a CS130 alternator. The basics would also apply to a gasoline powered Scout II.

Delco CS130 Installation

The Lester 7294 or the 7278 alternators are just Delco 12si alternators with different amperage ratings. The Lester numbers are just alternate, general part numbers for electrical components. There will also be an Delco/Remy part number and even a manufacturers rebuild part number. The Lester Catalog Company puts out yearly catalogs for automotive electrical components and gives each a Lester catalog number. Different versions of the same alternator will have it's on Lester number, so a 63 amp Delco 12si will have a different number than a Delco 94amp alternator, and the case clocking will also generate a different Lester number. So a Delco 12si 94amp alternator with a 3 o'clock plug position has a Lester number of 7294-3 while the same alternator with a 12 o'clock plug position has a Lester number of 7294-12. It makes for a lot of numbers but makes it easier to be specific when ordering new stock, as Lester numbers are primarily used by automotive parts manufacturers and retailers, not by the end customer usually. So if NAPA needs several Delco 12si 94amp alternators with a 12 o'clock plug position it will normally use a Lester number to order from the manufacturer, but when it sells you the same alternator it will sell it by the NAPA part number. If instead it were your local Chevrolet dealer again it would order by the Lester number, but sell the alternator to you with the Delco/Remy part number.

Also, try this link for a good write up on 10si and 12si alternators by Mad Electrical.

DELCO REMY models 10SI & 12SI alternators - Visual Identification and Differences

The SI alternators won't need a wiring adapter, but the CS alternators will need and adapter, or you have to rewire for a CS style plug. Easiest to just use the appropriate adapter. There are two CS adapters, one for a resistance wire distributor and the other for a non-resistance wire distributor. If you have points it will be a resistance wire, if electronic distributor it will be non-resistance wire adapter.

[AkioOhtori]

Great info! Thank you so much!

For better or worse this project got shelved for a bit. While I do want to upgrade my alternator eventually, I got the existing one tested and it works fine!?

I'll post the results when I get around to this. (Happy to have this as a reference for later!)