The 10SI series alternator was GM's first internally regulated alternator. Then as power demand went up GM introduced the12SI. The 10SI & 12SI have the same outside psyicial dimensions and will fit in place of each other but the 12SI uses wider stator, plus a better bridge rectifier to give the alternator greater output . Parts such a voltage regulator, brusholder and diode trio are the same both at idle and high RPM's

Heavy Duty Alternator Upgrade for Delco 10Si and 12Si Alternators

This kit was designed by our experts to maximize both the output and durability of your alternator. Every component is selected to revitalize your aging alternator, Not just for higher output either. Durability and a long life is just as important to us, and your charging system, as maximizing output. 

Stator

Where the POWER is Made.

It's common to underwind stators putting less wire giving you lots of output at the high end, but lower output at idle and greater heat problems. If you don't upgrade the stator, you don't upgrade the alternator. This gives you higher idle output without sacrificing peak performance or durability. Our stator is thicker and heavier than the stators used on factory units. This means your alternator will have more copper, higher amperage, and better durability.

Rectifier

Where DURABILITY is Tested, Rectifiers Convert AC current, that altetrnators make to DC current

We also use the beefiest rectifiers that will fit in the case. Stock units use 25-35 Amp rated diodes. We double that to 70 Amp rated diodes. That means our rectifiers are rated at a whopping 210 AMPS!. Some of our competitors will sell you an upgrade kit with a drop wound, high output stator and a STOCK RECTIFIER. Running a 105 Amp or 140 Amp stator with a 75 Amp rectifier is a sure way to burn up your alternator, your time, and your hard-earned money.

Regulator

The BRAINS of the Alternator.

A system is only as strong as its weakest link. 

This kit contains:
Heavy Duty 12SI Stator (fits in both the 10& 12 SI units)
Heavy Duty 12SI Rectifier (fits in both the 10& 12 SI units)
Heavy Duty Voltage Regulator with ignition wire activation
Brusholder assembly ( includes brusholder, springs and brushes)
Diode Trio (not shown)