TREMEC TKX, TREMEC Magnum, & SST A41 Conversion Kits for 1958-1964 GM B Body: Impala, Bel Air, Bonneville, Grand Prix, Catalina & Biscayne
Enjoy Life in Overdrive
Silver Sport Transmissions has the best-engineered kits to modernize the powertrain of your 1958-1964 GM B body. Our PerfectFit™ Kits bring the shifter handle to the factory-correct position for the best possible fit and our billet shifter tower provides short, crisp shifts.
Car shows, close friends, and good times are all within easy reach when you choose a TREMEC TKX 5-speed, T56 Magnum 6-speed, or Silver Sport Transmissions A41 4-speed automatic overdrive from SST!
The TREMEC TKX 5-Speed is the newest and most compact transmission from TREMEC. Capable of handling up to 600 lb-ft torque and 7,500 rpm shifts, the TKX is strong enough to handle most street applications. Our TKXs have been modified to give you a factory-correct shifter position so your car will retain the factory look. They also come with a crossmember to keep your driveline angles in spec. Find out why people call this powertrain upgrade the best improvement they've made to their car!
The TREMEC Magnum 6-speed is quickly gaining in popularity as more and more people opt for larger engines. The 6-speed has two overdriven gears and can handle up to 700 lb-ft torque and 7,800 rpm shifts. Although it's certainly capable of handling the abuse of the track, it's also great for everyday use. Our short throw shifter tower turns a great transmission into one of the best out there and our PerfectFit™ kit will let you keep a factory look with modern performance.
Silver Sport Transmissions A41 4-Speed Automatic is based on the GM 4L60E transmission and comes in three performance stages. It can handle anywhere from 450 to 650 lb-ft torque. It's an excellent alternative to replace the original automatic and with the overdrive, it is an impressive upgrade. Switch from a gas-saving economy mode to performance mode with a flip of a switch or go from performance to high performance, you set the custom shift points!
Use the tabs above to learn more about each transmission or use the Speed Analyzer to determine which transmission will fit your car and driving style the best.
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Tremec TKX PerfectFit™ for 1958-1964 GM B-Body
When you convert to the Tremec TKX 5 Speed, you will experience:
- Compact, rounded case - No cutting
- Capable of handling 600 lb•ft torque
- Capable of 7,500 rpm shifts
- 30-50% increase in fuel economy
- Low RPM cruising
- Reduced NVH (noise - vibration - harshness)
- Interchangeable with mechanical or hydraulic clutch actuators by removing just a few bolts, no need to tear down the transmission
- Designed for everyday street use - an ideal blend of brute strength and street manners
TKX Gear Ratios
Wide Ratio - 3.27, 1.98, 1.34, 1.00, 0.72
Close Ratio - 2.87, 1.89, 1.28, 1.00, 0.68 OR 0.81
Silver Sport Transmissions Overdrive Kit Overview
Driveshafts are no longer included on your order, but may be purchased seperately.
- TREMEC TKX 5 Speed Overdrive
- STX Shifters® - True offset for a factory-correct shifter position
- Pilot Bearing - Super heavy-duty needle roller type with lube seal for long life
- Installation Hardware - Every bolt you need is included and clearly labeled
- Isolator Mount - Rubber for vibration isolation or optional heavy-duty poly for track duty
- Crossmember - CAD designed, lightweight and box welded for rigidity. Better exhaust clearance and rigidity compared to tubular or aluminum variants.
- Speedometer Connection - Mechanical and electronic compatible
- Reverse Lights Connector - Waterproof connector
- Slip Yoke
- Detailed Installation Instructions - including free lifetime tech support
- Market Leading Warranty - learn more
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Auto to Manual Conversions and Optional Parts
- SST Advanced Friction™ Flywheel* - Billet steel, not cast steel, for improved durability and safety
- SST Advanced Friction™ Series II Clutch* - High performance, long life packages with easy pedal effort tailored to your needs
- Bellhousing* - Choose from titanium-aluminum OEM type or steel scatter shields that meet race safety requirements.
- Hydraulic Clutch Actuator Kit* - Modern technology with less pedal effort
- Master cylinder - high-quality
- Heavy-Duty concentric slave cylinder - 1,000,000 cycle service life
- Pre-engineered firewall mount for master cylinder - eliminates guess-work for easy installation
- Remote reservoir with hose
- Braided steel pressure hose
- Pedal pushrod and all hardware
- Detailed installation instructions
- Shifter Handle* - A variety of shifter sticks from classic to modern to choose from.
- Shifter Knob* - Available in white or black for that classic look. Engraved with 5-speed shift pattern.
- Fluid - Break-In Fluid, transmission fluid, and hydraulic clutch fluid available for purchase
*Required for Automatic to Manual Conversions
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Why buy from Silver Sport Transmissions?
- Fast Shipping
- Popular kits are in stock for short lead times
- Complete Kits
- Why go to multiple sources for parts? Make one phone call and get things going on your project now.
- Excellent Customer Service
- Lifetime tech support
- Knowledgeable staff
- Premium Components
- Only approved, high-quality parts are sold by SST.
- Engineering Know-How
- Only SST has experienced and licensed engineers on staff. We know what fits, what works and how to install it.
Call today and let us assemble a custom kit just for you, or complete a Quick Quote
T56 Magnum 6-Speed Basic Kit for GM
Highway Cruising Double Overdrive!
Download or print the installation manual here: Installation Manual
When you convert to the Tremec T56 Magnum 6 Speed, you will experience:
- 30-50% increase in fuel economy
- Low RPM cruising for greatly reduced driver fatigue and an improved highway driving experience. Road trips are fun again
- Reduced engine wear leading to longer engine life
- Cooler engine operating temperatures
- Reduced NVH (noise - vibration - harshness)
Tremec T56 Magnum Gear Ratios
2.66, 1.78, 1.30, 1.00, 0.80, 0.63
2.97, 2.10, 1.46, 1.00, 0.80, 0.63
Silver Sport Transmissions Basic Kit Overview
This is SST's Basic Kit with only the essentials included. It's perfect for builders able to fabricate or modify their own crossmember and tunnel hump.
Driveshafts are no longer included on your order, but may be purchased seperately.
Tremec T56 Magnum Kit Components
- Tremec T56 Magnum 6 Speed Double Overdrive
- 700 torque capacity wide or close ratio.
- Friction Lined Synchronizer Blocker Rings come standard for easy high RPM shifts
- Market Leading Warranty - learn more
- Optional Add the Front Shift Kit for bench seat clearance
- Slip Yoke
- Speedometer Connection
- Mechanical and electronic compatible
- Calibrated Speedo Cable or Electronic Speedo Connector - Your choice
- Reverse Light Connector
- Pilot Bearing
- Super heavy-duty needle roller type with lube seal for long life
- Isolator Mount
- Rubber for vibration isolation
- Installation Hardware
- Detailed Installation Instructions - including free lifetime tech support
- Market Leading Warranty - learn more
Optional components offered
- Reverse Lockout Control Module
- Heavy Duty Poly Isolator Mount Upgrade
- For track duty
- Hydraulic Clutch Actuator Kit - Modern technology with less pedal effort
- Master cylinder - high-quality
- Heavy-Duty concentric slave cylinder - 300,000 stroke service life
- Pre-engineered firewall mount for master cylinder - eliminates the guesswork for easy installation
- Remote reservoir with hose
- Braided steel pressure hose
- Pedal pushrod and all hardware
- Detailed installation instructions
- Flywheel
- Billet steel, not cast steel, for improved durability and safety.
- Clutch Kit
- High performance, long life packages with easy pedal effort tailored to your needs
- Bellhousing
- Titanium-Aluminum OEM type or steel scattershields that meet race safety requirements
- Shifter Handle
- Shifter Ball
- For aftermarket shifters, available in white or black for that classic look. Engraved with a 6-speed shift pattern.
Call today and let us assemble a custom kit just for you or buy now online!
A41 4-Speed Automatic Basic Kit for GM
Put it in drive and watch the gas stations go by.
The A41 4 Speed Automatic Transmission Basic Builder's Kit
This is the basic builder's kit, cutting and/or fabrication will be required for installation.
A41 Ratio: 3.06, 1.63, 1.00, 0.70
Available in three stages:
Stage 1 - 450 Torque
Stage 2 - 550 Torque
Stage 3 - 650 Torque
Features:
- Low RPM Cruising
- Great Shift Quality
- Dyno Tested
- Electronic Controller
- Lockup Torque Converter with Optional Stall Speeds
- No Tunnel Cutting
The A41 is an excellent way to replace your tired 904, 727, 518, Powerglide, TH350 (Turbo 350), TH400 (Turbo 400), 200R4 (200-4R) or 700R4 with modern technology that offers better acceleration and a 30% reduction in cruising rpms.
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COMPUSHIFT Sport
The COMPUSHIFT Sport is the next generation of transmission controllers.
- All the connectors - The COMPUSHIFT Sport transmission controller looms come with a full set of Plug and Play OEM Connectors for all supported transmissions - making installation effortless.
- Smart Phone Integration - COMPUSHIFT Sport brings you the first-ever smartphone integrated transmission controller. This makes programming dead easy – allowing programming via Android or iOS smartphones, tablets, PCs and Macs. Connectivity includes both Bluetooth and dual independent CAN bus networks. All software is included.
- Fully Customize Your Transmission - Get full and precise control of the shifting strategy for your transmission. COMPUSHIFT Sport and Pro are delivered with versatile factory-set programming for a wide variety of transmission and engine combinations. However, you can completely customize settings to your exact specifications.
COMPUSHIFT Sport Technical Specifications
Smart Phone / Tablet / Computer Integration:
- COMPUSHIFT Sport brings you the first-ever smartphone integrated transmission controller. This makes programming dead easy – allowing programming via Android or iOS smartphones, tablets, PCs and Macs. Connectivity includes both Bluetooth and dual independent CAN bus networks. All software is included.
Control:
- Get full and precise control of the shifting strategy for your transmission. COMPUSHIFT Sport and Pro are delivered with versatile factory-set programming for a wide variety of transmission and engine combinations. However, you can completely customize settings to your exact specifications.
- Fully adjustable shift speeds, shift feel and torque converter clutch control.
- Provides adjustable output for speedometer calibration.
Compatibility:
- COMPUSHIFT has the capability of communicating with many different factory and aftermarket engine controllers for quick plug and play setup. No wire splicing required.
- Uses industry-standard trouble codes
Ease of Setup:
- All The Connectors - The COMPUSHIFT Sport transmission controller looms come with a full set of Plug and Play OEM Connectors for all supported transmissions - making installation effortless.
- COMPUSHIFT software is upgradeable in the field via Bluetooth. Updates are available via Google Play, Kindle and the Apple App Store.
- Two full sets of calibration modes that can be selected by button or app.
- Transfer case switch input for shift / speedometer calibration in low range / 4WD vehicles.
Durability:
- Highly Water and Dust Proof - IP65 Rated
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Each Basic Kit comes with the correct components for your application and will include the following parts:
- Automatic Transmission - A41 (GM 4L60E / GM 4L65E Aftermarket replacement)
- COMPUSHIFT Sport Controller
- Dipstick and Tube - OEM Style
- Auxiliary Oil Cooler - High performance for Stage 2 and 3 only, Optional purchase for Stage 1 kits
- Bellhousing
- Lock Up Torque Converter - Electronically controlled, stall options available
- Throttle Position Sensor - Bolt-on unit provides throttle feedback to the computer with just 3 wires
- Rubber Cooler Lines
- Speedometer Cable - Mechanical Speedo Cable
- Hardware - High strength grade 8 fasteners standard
- Wiring - Plug & Play wiring harness
- Inspection Cover
- Slip Yoke
- Reverse Light Wiring
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