I want to upgrade my Alternator

[Classicman]

Hey Guy's , I have some questions that I want to know about my Alternator. I have 10si alternator on my Chevy 1972 BB 402. I want to upgrade to 12si alternator because is better. Also, I want to know what Voltage regulator I need to use for this new alternator or I keep the same regulator? I want to install a new digital OEM Radio , electric fans, A/C, headlights and more stuff that need more voltage.

Thanks

[WIDESIDE72]

Iirc a 10si and 12si are both internally regulated. Rhere should be no difference in he two if you have already converted from your old ext reg alt.

In case you havent Here is a link to the diagram

http://classicoldsmobile.com/forums/...n-trouble.html

There is probablya lot on this site on the subject as well. LMC sells a plug that goes i the end of the harness At the old ext reg so you dont have to modify your wiring as well as an adapter for the alt plug its self. Im sure other bendors sell them as well.
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[WIDESIDE72]

Marlan Davis from Hot Rod:

The Delco SI series integrally regulated alternators are a good retrofit for classic musclecars retaining conventional spark and fuel management. The 10SI design first appeared on some '69 GM cars and became standard equipment by the mid-'70s; it's available in outputs as high as 63 amps. The 12SI appeared in the early '80s, and some are rated up to 94 amps. Both can be rebuilt by the end user. Not only are the peak ratings higher than the first-generation externally regulated alternators, these units also produce much more juice at idle.

SI-series alternators were superseded in the mid-'80s by the CS design, many of which are rated in excess of 100 amps. Preferred for electronically managed engines, the CS is trickier to wire, many salvage-yard units don't have traditional 180-degree opposed mounting lugs, non-Delco remanufactured units often have durability problems, they aren't field-rebuildable by the end user, and they carry a much higher price tag.

For these reasons, you'll probably want an SI-series alternator. Yes, you must jumper the old external alternator hookups and change the plug at the alternator (see illustration). If you are not running a dash warning light or don't have the original resistance wire in the stock harness included with the factory gauge package, it will be necessary to add a diode to the No. 1 terminal circuit or the car won't shut off. The 94-amp 12SI units also require upgrading the stock 10-gauge charging wire to 8-gauge. One source for inexpensive wiring kits with wires, fusible links, connector bodies, terminals, diodes, and complete instructions is M.A.D. Enterprises (Springville, CA; 559/539-7128, www.madelectrical.com). M.A.D.'s cool Web site is chock full of wiring information and tech tips.



Read more: http://www.hotrod.com/techarticles/m...#ixzz2fe3TwRwy
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[425HP409]

Years ago I converted my GMC from a 63 amp 10SI to a 100 amp 27SI, by only modifying the brackets. This year I installed a factory GM serpentine belt system with a CS alternator. To simplify things, mainly the wiring, I had the alternator converted to a one wire configuration at my local alternator shop. I run a voltmeter as opposed to an amp meter in the truck, so everything works without any rewiring.
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