High quality upgrade alternator for the 96-01 DOHC SVT Cobra, and for the 03-04 Mach 1 and 2001 Bullitt. This alternator is built with quality parts, and is backed by a lifetime warranty!
For cars with a large amperage appetite look no further than our 250 amp option. These alternators are a BEAST and will satisfy even the biggest amperage appetites!
The Big 3 option is a wiring kit that replaces your factory power and ground cables with robust 0 gauge heavy duty, 100% copper welding cable. It also introduces a second ground cable and a fuse on the power cable. These cable kits are HIGHLY recommended as the stock wiring is only 10 gauge at it's smallest point which isn't even adequate for the stock alternator. Combine that with 20+ years of copper degredation and corrosion it's a recipe for disaster and an underperforming alternator. **Big 3 upgrade is REQUIRED on 250 amp units to retain warranty. If you don't purchase the wiring kit from us you will be required to provide proof of installation of a wiring upgrade on your vehicle in order for warranty to be approved.
***We build these alternators to order and usual build time is approximately 5 to 7 business days. If you need it faster than that, please let us know when you order and we will make every effort to accomodate you. We understand that people have race or show events they like to attend and we've been there. But, we have to know as early as possible in order to take action.
KMJ 4G Alternator For 96-01 Cobra, 03-04 Mach 1, 2001 Bullitt
A Lifetime Warranty is standard for ALL units sold and shipped to customers in the continental US. Lifetime warranty covers the original purchaser for defects in materials and workmanship. Should the unit fail to function we will repair or replace it free of charge minus shipping costs to us. Warranty does not cover improper installation or physical damage. Special coatings/finishes will be rebuilt using the original housings. International orders are not covered under warranty due to logistic expenses.
*See warranty and returns policy for complete details
Every KMJ Alternator is hand built to order. Please allow 5-7 business days for shipment. (8-10 days for special finishes or during sales)Expedited service available in some circumstances. Once order is placed it cannot be cancelled as we order parts for builds immediately upon purchase.

Reviews
Shipped within about 8-9 days of ordering. Packed very well. Drop in and connect wire and plug. Works like it should. Thank you
Alternator has worked flawlessly since install, went with a 200 amp unit. Heard a rumor that he would build them special for a marauder upon request and he did, showed up with the clutched pulley it’s supposed to have, making KMJ pretty much the only aftermarket support for upgraded marauder alternators.
I am extremely happy with my upgraded custom 4g alternator, the color is amazing and performance is spot on as advertised
The product works well and the customer support is awesome.