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Drivetrain› 4x4 Driveline Components

Advance Adapters, Inc

ALLISON TRANS/ATLAS 4SP ADAPTER WITH 700.00 CORE CHARGE

$593.75 $587.00 Save $6.75

SKU: A01D 50-9421

Out of Stock
Out of Stock
Free Shipping over $200
$100 Minimum Order
30 Days Return
INSTALL DIFFICULTY
DIY PRO SHOP

Moderate — 2–4 hours

Overview

The Advance Adapters 50-9421 is a transfer case adapter kit designed to couple an Allison 1000 (GM) 4WD 29-spline transmission to a GM NP205 transfer case. Constructed from steel with a natural finish, this adapter provides a new 29-spline input and 2.875 inches of adapter length. Advance Adapters offers these kits to simplify transmission swaps, allowing for the retention of the stock transfer case location. This product is sold as a kit and does not include mounting hardware.
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ALLISON TRANS/ATLAS 4SP ADAPTER WITH 700.00 CORE CHARGE

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

BrandAdvance Adapters, Inc
Part NumberA01D 50-9421

Videos

Advance Adapters New Process 205 (NP205) Input Gear Install

Advance Adapters New Process 205 (NP205) Input Gear Install

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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.

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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.

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.

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