Engines and Components› Engines, Blocks and Components

Cummins

4BT 3.9L Long Block Assembly

$5,999.99

SKU: 230828

In Stock
In Stock
Ships by Sep 13
Free Shipping over $200
$100 Minimum Order
30 Days Return
INSTALL DIFFICULTY
DIY PRO SHOP

Advanced — 4+ hours

Overview

The Cummins 4BT 3.9L Long Block Assembly is a premium replacement solution designed for Cummins applications. Featuring the 230828 block casting and 3933352 head casting, this long block assembly is engineered for performance, reliability, and durability. This brand-new long block provides the foundation for efficient and dependable operation in heavy equipment, machinery, or vehicles powered by Cummins engines.
Show original supplier description
The Cummins 4BT 3.9L Long Block Assembly is a premium replacement solution engineered for Cummins applications. This assembly utilizes the 230828 block casting and the 3933352 head casting, making it a robust foundation for rebuilding heavy equipment, industrial machinery, or vehicles equipped with Cummins engines. It is manufactured to the highest standards, guaranteeing a perfect fit and delivering superior functionality and long-term use. The assembly weighs approximately 500 lbs. This product is sold as a genuine OEM part. Buyers are responsible for researching and ensuring the part's fitment for their specific application before purchasing. Returns due to non-fitment are accepted with a restocking fee, and the customer is responsible for return shipping costs.

Product descriptions are provided by our supplier partners and may not always be perfectly accurate. Not sure this fits? or call (760) 282-4645 and we’ll verify before you order.

Fitment

Fitment Guaranteed

Don’t gamble
on fit.

Log your build in the MOTORMIA app and we’ll guarantee this part fits your exact setup — or your money back, return shipping covered.

Available on iOS & Android

Specifications

BrandCummins
Part Number230828
CategoryEngines and Components

We’re here — turning wrenches, just like you.

Call us, follow along, or come say hi.

(760) 282-4645 Instagram Google

Buy with Confidence

Returns & Fitment

Built for enthusiasts. Every order is backed by our 30 day return window on eligible items. Unused and uninstalled products may be returned with approved RMA and no restocking fees when received in new condition. Orders placed through the MOTORMIA app with a complete build qualify for our Fitment Guarantee — free return shipping if the part doesn’t fit your exact setup. The guarantee covers fit only; installation must follow manufacturer instructions, and we recommend a qualified shop for parts marked Difficulty 4–5.

View Full Return Policy

Shipping

Orders are processed in 1–3 business days. In stock parts ship promptly from our partner network. Special-order items either aren’t currently stocked or are built to your spec — expect 4–6 weeks. If a part goes on backorder while your order is in the queue, we’ll reach out and work through discounted alternatives together.

Free shipping over $200 in the continental US. Alaska, Hawaii, U.S. territories (Puerto Rico, U.S. Virgin Islands, Guam, American Samoa, and the Northern Mariana Islands), and international orders carry surcharges — most appear at checkout. Some exceptions (LTL freight, or suppliers who quote freight only after we place the order) won’t. In those cases we’ll reach out with the exact charge before your order moves forward.

View Full Shipping Policy