Featured Products

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Mishimoto

Mishimoto 11-16 Ford 6.7L Powerstroke Aluminum Primary Radiator - MMRAD-F2D-11V2

MSRP:

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Now: (Inc. Tax)

MSRP: $1,471.00

Was:

Now: $1,337.95
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ARP

ARP 01-10 6.6L GM Duramax Diesel Head Stud Kit - 230-4201

MSRP:

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Now: (Inc. Tax)

MSRP: $814.20

Was:

Now: $757.95
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ICON

ICON 2017+ Ford F-250/F-350 2.5in Stage 5 Suspension System - K62515

MSRP:

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MSRP:

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Now: $4,964.95
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Wehrli

Wehrli 17-19 Chevrolet 6.6L L5P Duramax High Flow Intake Bundle Kit Stage 2 - Red - WCF100441-RED

MSRP:

Was:

Now: (Inc. Tax)

MSRP: $1,600.00

Was:

Now: $1,574.95
King Shocks

King Shocks 2005+ Ford F-250 4WD Front 2.5 Dia Remote Res Coilover Conversion w/Adjuster (Pair) - 25001-146A

MSRP:

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MSRP:

Was:

Now: $2,545.95
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ICON

ICON 2017+ Ford F-250/F-350 2.5-3in Stage 5 Coilover Conversion System - K63145

MSRP:

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Now: (Inc. Tax)

MSRP:

Was:

Now: $7,176.95
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Mishimoto

Mishimoto 2019+ Dodge Ram 6.7L Cummins Intercooler Kit / BK Cooler - WBK Pipes - MMINT-RAM-19KBKWBK

MSRP:

Was:

Now: (Inc. Tax)

MSRP: $2,397.00

Was:

Now: $2,179.95
Garrett

Garrett GT3794VA Turbo Kit - Chevy Duramax 6.6L 2004.5-2009 Stage 1 AVNT - 773540-5001S

MSRP:

Was:

Now: (Inc. Tax)

MSRP: $3,102.82

Was:

Now: $2,420.95

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If it’s in stock, you’ll see it. If it’s out of stock, it’ll be clearly marked — no surprises, no guessing.

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Why Underworld Diesel?

The diesel world is packed with slow shipping, outdated sites, and customer service that disappears the second you hit “Place Order.” That's not how we operate.

We’re diesel people. Real trucks, real wrenching, real experience. We know what works, what fails, what’s junk, and what actually makes your rig run harder.

Everything on our site pulls from live inventory — if it shows **In Stock**, it’s ready to go. If it shows **Out of Stock**, that’s exactly what it is. Straight answers. Zero games. Zero bullshit.

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