7.3L Godzilla Dual Alternator Bracket Kit | 400A Upgrade | Mechman®
Ford 7.3L Godzilla · Dual Alternator
More Power for Your 7.3L Godzilla — Without Losing the Factory Alternator
Ford's 7.3L "Godzilla" gas V8 is a workhorse — and the rigs built on it tend to ask a lot of the electrical system. A Mechman dual-alternator bracket kit adds a 400-amp second alternator while keeping the factory unit in place, so you get serious extra headroom with a clean, bolt-on install.
Why the Godzilla runs short on power
The 7.3L Godzilla shows up everywhere demand is high: Super Duty work trucks, Class A motorhome and stripped chassis, cutaway vans, and engine swaps. Those builds stack inverters, house batteries, lighting, winches, lift gates, A/C, and audio onto a single factory alternator that was sized for a stock vehicle — not for everything owners actually bolt on.
When total demand climbs past what one alternator can supply, voltage sags, batteries discharge to cover the gap, and accessories start misbehaving. The fix isn't to overwork a single unit — it's to add a second alternator dedicated to the extra load.
The dual-alternator answer: keep the factory unit, add 400 amps
This kit mounts a high-output 400-amp B7796400B alternator alongside the factory alternator — a true dual setup. The factory unit keeps handling the vehicle's original systems while the Mechman 400A feeds your added loads, so the whole system holds voltage even when everything's running at once.
What's in the kit
- Cast dual-alternator bracket
- B7796400B 400-amp alternator
- Mounting hardware
- Idler pulley
- Drive belt
Output Added
400A
Alternator
B7796400B
Setup
Dual
Fitment
2020+ 7.3L
A clean, bolt-on install
The cast bracket locates the second alternator using the kit's hardware and idler pulley, and the kit ships with the belt to drive it. Mechman provides a downloadable installation manual (INSTR-GZDB-20) that walks the assembly and details proper spacer usage for correct belt alignment — the same complete, no-guesswork approach across the Mechman bracket-kit line. Every alternator is built in Knoxville, Tennessee, with optional 1-year, 2-year, and lifetime internal-parts warranty terms available at checkout.
Shop the kit
Ford™ 7.3L Godzilla · Dual · 400A
7.3L Godzilla Dual Alternator Bracket Kit
$799.00 · includes 1× B7796400B
Complete bolt-on dual kit for 2020+ Ford 7.3L gas engines — cast bracket, 400A alternator, idler pulley, hardware, and belt.
View Kit →Frequently asked questions
Will this fit my 7.3L Godzilla?
It's designed for 2020-and-up Ford 7.3L gas (Godzilla) engines and adds the second alternator while keeping the factory unit. The included belt suits F-series and similar applications; E-series vans may need a different belt length because of chassis-specific routing, so confirm your routing against the included instructions.
Does it replace my factory alternator or add to it?
It adds to it. This is a true dual-alternator setup — the factory alternator stays in place and keeps running the vehicle's original systems, while the Mechman 400-amp B7796400B handles your added electrical loads.
How much power does it add?
The kit adds a 400-amp alternator on top of your factory output. That's a large block of dedicated headroom for inverters, house batteries, lighting, winches, A/C, and audio — the loads that pull a single-alternator system flat.
Is everything included, or do I need extra parts?
It's a complete kit: cast dual-alternator bracket, the B7796400B 400-amp alternator, mounting hardware, idler pulley, and a drive belt. It's built to bolt on without sourcing parts separately.
How hard is the install?
It's a bolt-on using the supplied bracket, hardware, idler, and belt. Mechman includes a downloadable installation manual (INSTR-GZDB-20) that covers the assembly and proper spacer usage for correct belt alignment. If you're comfortable with belt and accessory work, it's a straightforward job.
Where is it made and is it warrantied?
Every Mechman alternator is built in Knoxville, Tennessee. Optional 1-year, 2-year, and lifetime internal-parts (brushes, bearings, rectifier, regulator) warranty terms are available at checkout.
Need a hand choosing?
Not sure how much output your build needs?
Tell us your engine, the accessories you run, and your power goals, and we'll point you to the right setup.
Trademark Disclaimer: Ford™ and Godzilla™ are trademarks of their respective owners. All company, product, and service names used here are for identification purposes only and do not imply endorsement or ownership. Mechman manufactures aftermarket charging components compatible with the applications listed.