American Powertrain Tremec T-56 Magnum Manual Transmissions and Installation Kits for 1955-1957 BEL AIR - COGM-B1J

Name: American Powertrain Tremec T-56 Magnum Manual Transmissions and Installation Kits
Brand: American Powertrain
SKU: AWR-COGM-B1J
Price: 4995.00 USD
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Part Number: AWR-COGM-B1J

$4,995.00

American Powertrain Tremec T-56 Magnum Manual Transmissions and Installation Kits

Combo, ProFit, Wide Ratio, T-56 Magnum, 6-Speed, 1955-57 Tri-5 Chevy, 2.97:1 First Gear, 0.50:1 Sixth, Kit
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American Powertrain Tremec T-56 Magnum Manual Transmissions and Installation Kits for 1955-1957 BEL AIR - COGM-B1J

AWR-COGM-B1J

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Part Number: AWR-COGM-B1J

Estimated Ship Date: Mar 27, 2026

$4,995.00

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Overview

Brand:

American Powertrain

Manufacturer's Part Number:

COGM-B1J

Part Type:

Manual Transmission and Installation Kit Combos

Product Line:

American Powertrain Tremec T-56 Magnum Manual Transmissions and Installation Kits

Summit Racing Part Number:

AWR-COGM-B1J

UPC:

041969292815

Transmission Included:

Yes

Number of Gears:

Input Shaft Diameter:

1.125 in.

Input Spline Quantity:

Output Shaft Spline Quantity:

Bellhousing Included:

Yoke Included:

Yes

Shifter Included:

Yes

First Gear Ratio:

2.97:1

Second Gear Ratio:

2.10:1

Third Gear Ratio:

1.46:1

Fourth Gear Ratio:

1.00:1

Fifth Gear Ratio:

0.74:1

Sixth Gear Ratio:

0.50:1

Case Material:

Aluminum

Crossmember Included:

Yes

Crossmember Material:

Aluminum

Crossmember Color:

Natural

Transmission Mount Included:

Yes

Transmission Mount Type:

Polymer

Transmission Tunnel Patch Included:

Pilot Bushing Included:

Yes

Pilot Bushing Material:

Steel

Pilot Bushing Type:

Roller

Speedometer Cable and Gear Included:

Backup Light Connector Harness Included:

Yes

Mounting Hardware Included:

Yes

Fabrication Required:

Yes

Quantity:

Sold as a kit.

Notes:

X-Factor aluminum modular crossmember, 1000 HP certified, offers clearance for 3.5 in. diameter exhaust systems. Designed for electronic or mechanical speedometers (7-tooth). 700 ft.-lbs. torque capacity. Requires bellhousing adapter or engine specific bellhousing. Shifter stick not included.

American Powertrain Tremec T-56 Magnum Manual Transmissions and Installation Kits

American Powertrain Tremec T-56 Magnum manual transmissions and installation kits are designed to withstand up to 700 lbs.-ft. of torque. Their gears feature substantially increased face widths and 2-piece laser-beam welded construction, allowing for greater control of the tooth angles, pitch, and alignment. The transmissions also include a bolstered one-piece countershaft to resist distortion, and a stronger input shaft.

Magnum's new synchronizers are built with fine-tooth angles, redesigned shift forks—and an extensively modified transmission case to prevent leaks under high-stress conditions and increase overall power-handling capabilities. Nearly two dozen models are available; choose the kit recommended for your vehicle application.

Kits include:

* Cryo-hardened steel driveshaft slip yoke with 1330 style U-joint
* Mechanical speedometer conversion
* VSS wiring harness for electronic speedometer of EFI ECU
* Reverse light wiring, weather seal harness, non-polar
* Reverse lockout wiring harness
* ISO-X ballistic, low-profile transmission mount
* Steel roller pilot bearing
* White shift knob with black 6-speed shift pattern