Drivetrain› Automatic Transmissions and Components

B&M Racing (Holley)

TRANSMISSION SPEEDO PORT PLUG GM TH350

$49.56

SKU: B056 20299

In Stock
In Stock
Ships by Jun 15
Free Shipping
Non-Returnable Item
INSTALL DIFFICULTY
DIY PRO SHOP

Easy — 1–2 hours

Description

The B&M Racing 20299 is a billet aluminum speedometer port plug designed for GM TH350, TH350c, Powerglide, Muncie M-20, and Aisin AY6 transmissions. This plug is used to block the mechanical speedometer gear port when upgrading to an electronic speedometer. It features a black Mil-Spec anodized finish and includes a replaceable Buna-N-rubber o-ring for leak prevention.

Fitment

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Specifications

BrandB&M Racing (Holley)
Part NumberB056 20299

Buy with Confidence

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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