Diesel Power Source® Cummins 12-Valve Exhaust Manifold Complete Hardware & Gasket Upgrade Kit (SKU 1229)

Diesel Power Source® Cummins 12-Valve Exhaust Manifold Complete Hardware & Gasket Upgrade Kit. It includes every gasket and fastener needed for both the manifold-to-head install and the T3 turbo flange install — sourced together so you don't have to chase parts mid-build.

This kit replaces the standard flange bolts found in the manifold's base hardware kit with a full stud-and-nut configuration, the preferred mounting method for high-EGT applications. Multi-Layer Steel (MLS) gaskets resist burnout, blow-through, and warping far better than single-layer alternatives, and both divided and non-divided T3 turbo gaskets are included so the kit fits either housing style.

Why Upgrade From the Base Hardware Kit

The base hardware kit shipped with the DPS T3 12V manifold gets the manifold mounted to the head — but it doesn't include MLS gaskets, turbo flange hardware, or the gaskets required to bolt your turbo on. This upgrade kit adds all of those components in a single SKU.

Stud-and-Nut Mounting

Studs provide more consistent clamping load than bolts and resist fastener fatigue from repeated thermal cycling — critical for an exhaust manifold that sees hundreds of heat cycles a year. Studs also make future manifold removal far easier; you back off nuts instead of breaking loose corroded bolt threads in the head.

Multi-Layer Steel Gaskets

MLS gaskets use stacked stainless layers to seal the variable surfaces between the manifold and head. They handle higher boost, higher EGTs, and more aggressive tuning than single-layer gaskets without burning through or warping.

Both T3 Gasket Styles Included

Whether your turbo runs a divided or a non-divided T3 housing, the correct gasket is in the box. No second order, no waiting on shipping when the truck is mid-build.

Hardware for Both Stock and Aftermarket Turbos

The kit includes the standard turbo mounting studs that fit either a stock-style turbo or an aftermarket S300-style T3 turbo. For aftermarket S300 installs, the kit also includes one longer through-stud that passes through two mounting holes on the S300 turbo and is secured with a nut on each side. If you're running a stock-style turbo, the long stud isn't needed and you simply leave it unused. Either way, you don't need to specify which turbo you're running at checkout.

Who This Kit Is For

• Ford Cummins (Fummins) swap builders — F250, F350, Excursion, and other Ford trucks with 12V Cummins conversions
• RV and motorhome owners running the 5.9L 12-valve Cummins
• School bus and commercial bus operators with 12V Cummins applications
• Industrial and marine applications requiring a low-rear T3 turbo position
• Builders running stock-style turbos or aftermarket S300-style T3 turbos
• Builders who want all install hardware and gaskets in a single purchase

Key Features

• Full stud-and-nut manifold mounting — replaces the base kit's standard flange bolts
• Multi-Layer Steel manifold gaskets — built for high boost and high EGTs
• Non-divided T3 gasket 
• Hardware fits stock or S300 turbo — no need to specify which turbo at checkout
• Complete turbo mounting hardware — studs, bolts, nuts, oil drain gasket
• Direct fit for the DPS Fummins / Chummins / RV T3 Manifold (MAN0170) — no machining or modifications
• Single-source convenience — every gasket and fastener for the install in one SKU

Benefits

• Reduces manifold-bolt loosening and fastener fatigue from repeated heat cycling
• Improves long-term sealing under boost, towing, and performance tuning
• Makes future manifold removal easier — back off nuts instead of fighting seized bolts
• Eliminates the need to source MLS gaskets and stud kits from multiple suppliers
• One kit covers stock and aftermarket turbo configurations
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