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Drivetrain› Manual Transmissions and Components

Tracy Performance

Muncie M20/M21/M22 Transmission Case

Name: Muncie M20/M21/M22 Transmission Case
Brand: Tracy Performance
SKU: FMCASE-661

$437.99 $368.59 Save $69.40

SKU: FMCASE-661

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$100 Minimum Order

Non-Returnable Item

DIY PRO SHOP

Moderate — 2–4 hours

Overview

The Tracy Performance transmission case is an OE style factory replacement for Muncie M20, M21, or M22 4-speed transmissions. This case features the original casting number 3925661, along with U.S. PATENT and GENERAL MOTORS CORP. markings. It comes with both fill and drain plugs already drilled and tapped.

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The Tracy Performance Muncie M20, M21, M22 4-speed transmission case is a GM licensed, OE style factory replacement designed for damaged or broken original cases. This transmission case is a direct reproduction, featuring the original casting number 3925661, with U.S. PATENT and GENERAL MOTORS CORP. cast directly into it, ensuring an authentic appearance. This reproduction case comes pre-drilled and tapped for both fill and drain plugs, simplifying the installation process. It is designed to maintain the integrity and functionality of your classic Muncie 4-speed transmission. Specifically, this case fits 1970 through 1974 Chevrolet Chevelle models.

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

Brand	Tracy Performance
Part Number	FMCASE-661
Category	Drivetrain

Videos

General Motors 4 Speed Guide

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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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