Tremec T-56 Magnum, TKX and TKO transmissions use a Ford speedometer drive and require this adapter or a custom speedometer cable. This package is the easiest and most economical solution to connect to your existing GM 7/8" threaded cable to the transmission. This two piece design incorporates a double O-ring seal for the transmission case opening, as well as, an internal seal to prevent fluid from leaking through where the cable attaches. The drive spindle is a solid steel swiss machined part for extra strength and accuracy.

Connect your mechanical speedometer the right way. Bowler’s Made-in-USA adapter is the most accurate, leak-proof, and durable solution for Tremec T56 Magnum, TKX, and TKO transmissions — never settle for imported versions that leak, crack, or misread.

When ordering, we will need you to list your tire size (ex: 295/45-15 or overall height), as well as your rear end ratio, so we can get you the proper driven gear.

Bowler Performance Transmission is a Tremec Elite Distributor. Be sure and check us out for all your transmission needs.

Works With

Tremec Magnum
Tremec TKO & TKX
Tremec T-5
Legend Gear and Transmission's LGT-700

Available In The Following Tooth Counts

16T Gear - Purple
17T Gear - White
18T Gear - Yellow
19T Gear - Pink
20T Gear - Black
21T Gear - Red

Features

Made in the USA — precision-machined for accuracy
Fits Tremec T56 Magnum, TKX, TKO, T5, and LGT-700
Converts Ford-style drive to GM 7/8" threaded mechanical cable
Two-piece design with dual O-ring case seal
Internal seal to prevent oil leaks through cable connection
Swiss-machined solid steel spindle
Most economical and most accurate solution available
Available in multiple gear tooth counts
Works with factory and aftermarket GM speedometer cables

What’s Included

Mechanical speedometer adapter (two-piece assembly)
Solid steel machined drive spindle
Double O-ring seal
Internal cable seal
Installed driven gear (based on tire & axle ratio info)

Bowler’s Mechanical Speedometer Adapter is the most proven and reliable way to connect a GM 7/8" threaded mechanical speedometer cable to modern Tremec transmissions. Tremec T56 Magnum, TKX, and TKO units use a Ford-style speedo drive, requiring either a custom cable or an adapter. This Made-in-USA adapter is the strongest, most accurate, and most leak-proof solution available — superior to imported alternatives that commonly leak or wear prematurely.

This precision-machined kit uses a solid steel, Swiss-machined spindle for accuracy, a double O-ring seal to prevent case leakage, and an internal seal to stop fluid from traveling up the cable. This ensures long service life, consistent speedometer readings, and zero drivetrain mess.

When ordering, enter your drive tire size (example: 295/45-15 or overall height) and rear axle ratio. We’ll calculate your correct driven gear to match your vehicle combination.

This adapter is used by top builders worldwide and remains the simplest, most economical, and most dependable way to run a mechanical speedometer with modern Tremec gearboxes.

Why Choose Bowler vs Imported Copies

Most low-cost adapters on the market are imported and prone to:

leaking around the case opening
internal seal failure
inaccurate speed readings
weak drive spindles

Bowler’s adapter is 100% Made in the USA, Swiss-machined, and proven in thousands of builds with exceptional durability and accuracy.

Bowler - Tremec TKX, TKO, 3550, T-45, T-56 & T-56 Magnum Speedometer Hole Block Off Plug

Bowler Performance Mechanical Speedometer Adapter for Tremec T56 Magnum, TKX & TKO – Made in USA