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Tools› Engine-Related

GForce

TH400 Transmission Mock-Up Block

$270.24 $234.99 Save $35.25

SKU: GF-MUT-TH400

In Stock
In Stock
Ships by Sep 9
Free Shipping over $200
$100 Minimum Order
30 Days Return
INSTALL DIFFICULTY
DIY PRO SHOP

Easy — 1–2 hours

Overview

The GForce GF-MUT-TH400 is a TH400 transmission mock-up block designed for accurate transmission mounting and yoke positioning. This tool allows for precise placement of TH400 transmissions found in GM cars and trucks from 1964-1990. It is constructed from durable steel and can withstand welding heat.
Show original supplier description
The GForce GF-MUT-TH400 is a TH400 Swap Block Transmission Mock Up Block that utilizes a patent-pending tab-and-slot design to provide accurate transmission mounting and yoke positions. This lightweight tool comes disassembled, making it easy to ship and store. This mock-up block is designed to accomplish accurate placement of TH400 transmissions commonly found in GM vehicles from 1964 to 1990. It features a rear mount plate suitable for short-tail TH400 transmissions, with the option to attach a tail shaft to the rearmost upright plate if a long tail is required. Utilizing this mock-up block eliminates the need to manually position a heavy transmission for fitment and fabrication of components like crossmembers. It is made from durable steel construction, which resists heat from welding, allowing custom crossmembers to be fabricated in close proximity to the block, unlike foam alternatives. Specifications include a weight of 18 lbs and shipping dimensions of 32 x 21 x 6 inches. The finish is metal, and mounting hardware is not included.

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-MUT-TH400
CategoryTools

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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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