Tools› Engine-Related

GForce

Cummins Conversion Kit for C Series Trucks

$1,520.00

SKU: GF-GMC3-KIT

In Stock
In Stock
Ships by Sep 9
Free Shipping over $200
$100 Minimum Order
30 Days Return
INSTALL DIFFICULTY
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Professional / shop required

Overview

The GForce GF-GMC3-KIT is a Cummins conversion kit designed for a smooth diesel engine swap. It includes a transmission adapter and flexplate to mate a TH400, 700R4, or 4L80E transmission to a 1989-2002 6BT 12-valve or 24-valve Cummins engine. This kit is compatible with 1973-1987 C Series 2WD trucks.
Show original supplier description
The G Force Performance Products GF-GMC3-KIT is engineered to facilitate a smooth Cummins diesel engine swap into 1973-1987 GM C Series 2WD trucks. This comprehensive kit includes essential components such as a transmission adapter and flexplate, designed to seamlessly connect a TH400, 700R4, or 4L80E transmission to 1989-2002 6BT 12-valve or 24-valve Cummins engines. Key components within this kit include the GF-C-S Adapter and Flexplate, which ensures proper alignment between the 5.9L Cummins engine and the specified Chevrolet automatic transmissions. Additionally, the kit provides a premium grade bellhousing adapter bolt kit (GF-BoltKitAdapter) with 9 bolts, a Flexplate Bolt Kit (GF-BoltKitFP) with 8 bolts (12mm x 1.25, 25mm underhead length), and a Starter Bolt Kit (GF-BoltKitStarter) with 4 steel, zinc-plated bolts and 3 washers, all constructed to strict engineering quality standards. Mounting hardware is included, and the product is noted to ship in two separate boxes. G Force emphasizes their role in engineering bold solutions for easier installation without compromising quality.

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

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Specifications

BrandGForce
Part NumberGF-GMC3-KIT
CategoryTools

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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.

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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.

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