Description
Product Overview
The FTI Performance TH400 Level 4 Transmissions TH400-4K21 is built for serious Chevy performance applications that need a strong TH400 racing transmission with full manual control, launch consistency, and major supporting components included in one package. As part of the FTI Performance TH400 Level 4 Transmissions line, this kit is designed for drag racers, weekend bracket racers, high-powered street cars, mud trucks, race-prep shops, and performance drivetrain builders.
This transmission kit is identified by Manufacturer’s Part Number TH400-4K21, Summit Racing Part Number FTI-TH400-4K21, and UPC 887753824790. These identifiers help racers, mechanics, performance shops, engine builders, chassis builders, transmission installers, service departments, and drivetrain specialists confirm the correct FTI TH400 Level 4 kit before ordering.
The transmission features a 3-speed configuration, Chevy bellhousing bolt pattern, reverse shift pattern, and full manual valve body. This setup is intended for performance applications where the driver needs direct gear control, quick gear changes, and predictable race-focused operation.
The included trans-brake is a key drag racing feature. It supports controlled launch setup when properly wired, configured, and matched with the correct converter, rear gear, tire size, shifter setup, and vehicle combination.
This kit includes a 3,400–3,800 rpm stall billet torque converter equipped with a mechanical diode and balloon plate. That converter detail is important for buyers matching the transmission to engine powerband, camshaft, vehicle weight, rear gear, tire size, launch rpm, and track use.
The kit also includes FTI’s 3-gallon RacerPak of performance ATF, listed as 12 qt. of transmission fluid, plus a locking dipstick and tube. It also includes a complete cooler kit with the cooler, 15 ft. of line, hose ends, and fittings.
The transmission uses a deep natural aluminum pan, slip-on/bolt-on yoke style, 30-spline hardened steel TH350/400-style input shaft, 2.43 first gear ratio, billet steel clutch hub, OEM-style black aluminum case, and case-fill location.
FTI TH400 Level 4 transmissions include performance-focused features such as a 34-element intermediate sprag, performance clutches and steels, high-flow pump, race-prepped stock case, deep aluminum pan, billet forward clutch hub, heavy-duty intermediate retainer, and 4-clutch intermediate pack.
The flexplate is not included, the transmission controller is not included, and the wiring harness is not included, so buyers should confirm all required supporting components before installation.
Fitment and Application Details
The FTI Performance TH400-4K21 Level 4 transmission kit should be matched carefully to the intended Chevy racing or high-performance application before ordering. TH400 fitment can vary by vehicle year, engine platform, bellhousing setup, converter requirements, flexplate compatibility, starter arrangement, yoke style, mount location, crossmember position, driveshaft length, cooler routing, shifter setup, fluid fill location, trans-brake wiring, and SFI safety requirements.
Important fitment details to verify include vehicle year, make, model, engine platform, Chevy bellhousing bolt pattern, TH400 platform compatibility, torque converter fitment, 3,400–3,800 rpm stall suitability, converter bolt pattern, crankshaft pilot fitment, flexplate compatibility, starter setup, 30-spline hardened steel TH350/400-style input shaft compatibility, slip-on/bolt-on yoke requirements, transmission mount location, crossmember position, driveshaft length, reverse shift pattern, full manual valve body operation, shifter compatibility, trans-brake wiring, launch setup, cooler placement, cooler line routing, hose end and fitting compatibility, fluid fill requirements, SFI 4.1/30.1 compliance needs, and race-class rules.
Because the torque converter is included, buyers should confirm that the 3,400–3,800 rpm stall billet converter matches the engine output, camshaft profile, torque curve, vehicle weight, rear gear, tire size, launch rpm, and intended racing use.
Because the flexplate is not included, buyers should confirm the correct flexplate for the engine, crankshaft, converter bolt pattern, balance requirement, and starter setup.
Because the trans-brake is included, buyers should confirm activation method, switch setup, wiring, shifter compatibility, staging procedure, electrical readiness, and sanctioning-body rules before installation.
Because the complete cooler kit is included, buyers should confirm cooler mounting location, airflow, line routing, hose end compatibility, fittings, clearance, and installation path before use.
For a complete installation, additional components may be required, including a flexplate, shifter, shifter cable, trans-brake wiring, transmission mount, crossmember hardware, driveshaft/yoke components, race safety equipment, and vehicle-specific installation hardware.
Build Quality and Reliability
The FTI Performance TH400 Level 4 Transmissions TH400-4K21 is built for buyers who need a strong TH400 racing transmission package with full manual control and the major supporting components needed for a serious performance build. The Level 4 line is designed for demanding racing and high-output performance use.
The full manual valve body gives the driver direct control over gear changes, while the included trans-brake supports consistent launch performance when correctly installed and configured.
The 900 horsepower rating gives this transmission strong appeal for serious street/strip and racing applications when matched correctly with the engine, converter, cooling system, rear gear, tire size, and vehicle weight.
FTI TH400 Level 4 transmissions feature a 34-element intermediate sprag, performance clutches and steels, high-flow pump, race-prepped stock case, deep aluminum pan, billet forward clutch hub, heavy-duty intermediate retainer, and 4-clutch intermediate pack.
The included 3,400–3,800 rpm stall billet torque converter with mechanical diode and balloon plate adds high-value converter support for compatible racing setups.
The included complete cooler kit, 15 ft. of line, hose ends, fittings, FTI RacerPak performance ATF, and locking dipstick and tube make this package especially practical for builders who want more than a bare transmission.
The SFI 4.1/30.1 rating gives competition buyers an important safety-focused specification to confirm against class and track requirements.
What Makes This Transmission Kit a Strong Choice
The FTI Performance TH400-4K21 Level 4 transmission kit is a strong choice for buyers who need a compatible Chevy TH400 racing transmission package with full manual operation and launch-control capability.
The 900 horsepower rating supports serious performance applications when properly matched.
The included 3,400–3,800 rpm stall billet torque converter adds major package value.
The included trans-brake supports consistent drag racing launches when correctly installed.
The included complete cooler kit helps buyers plan transmission temperature control.
The included 12 qt. FTI performance ATF and locking dipstick and tube make the kit more complete than a transmission-only purchase.
The 2.43 first gear ratio, 30-spline hardened steel input shaft, and billet steel clutch hub provide important strength and setup details.
The exact TH400-4K21 manufacturer part number, FTI-TH400-4K21 Summit Racing part number, and UPC 887753824790 support accurate product identification before ordering.
Ideal Buyers and Use Cases
The FTI Performance TH400 Level 4 Transmissions TH400-4K21 is ideal for drag racers, weekend bracket racers, mud truck builders, high-powered street car owners, race teams, chassis builders, engine builders, race-prep garages, performance shops, transmission installers, service departments, and drivetrain specialists who need a compatible TH400 Level 4 racing transmission kit.
It is suitable for compatible Chevy applications requiring a 3-speed TH400 automatic transmission, reverse shift pattern, full manual valve body, trans-brake, 900 horsepower rating, 3,400–3,800 rpm stall billet converter, complete cooler kit, 12 qt. ATF, locking dipstick, 2.43 first gear ratio, 30-spline hardened steel input shaft, billet steel clutch hub, and SFI 4.1/30.1 rating.
This product is useful for drag cars, bracket racing vehicles, high-powered street/strip builds, mud trucks, purpose-built race cars, and performance drivetrain projects where a complete TH400 racing package is preferred.
It is also a practical choice for professional builders confirming supporting components such as the flexplate, shifter, trans-brake wiring, mount, crossmember, driveshaft/yoke setup, cooler mounting, fittings, and race safety requirements.
The best buyer for this transmission kit is someone who can confirm the Chevy engine fitment, converter suitability, flexplate requirements, 30-spline input, slip-on/bolt-on yoke, trans-brake wiring, shifter setup, cooling system, SFI requirements, and drivetrain layout before ordering.
Technical Specifications
| Specification | Details |
|---|---|
| Product Name | FTI Performance TH400 Level 4 Transmissions TH400-4K21 |
| Brand | FTI Performance |
| Manufacturer’s Part Number | TH400-4K21 |
| Part Type | Automatic Transmissions |
| Product Line | FTI Performance TH400 Level 4 Transmissions |
| Summit Racing Part Number | FTI-TH400-4K21 |
| UPC | 887753824790 |
| Number of Gears | 3 |
| Transmission Platform | TH400 |
| Bellhousing Bolt Pattern Manufacturer | Chevy |
| Transmission Shift Pattern | Reverse |
| Valve Body Style | Full manual |
| Transmission Advertised Horsepower Rating | 900 |
| Torque Converter Included | Yes |
| Advertised Flash Stall Rating | 3,400–3,800 rpm |
| Torque Converter Detail | Billet torque converter with mechanical diode and balloon plate |
| Flexplate Included | No |
| Transmission Controller Included | No |
| Wiring Harness Included | No |
| Transmission Cooler Included | Yes |
| Cooler Kit Detail | Cooler, 15 ft. of line, hose ends, and fittings |
| Trans-Brake Included | Yes |
| Lockup Compatible | No |
| Transmission Pan Style | Deep |
| Transmission Pan Material | Aluminum |
| Transmission Pan Finish | Natural |
| Yoke Style | Slip-on/bolt-on |
| Input Spline Quantity | 30 |
| Input Shaft Material | Hardened steel |
| Input Shaft Style | TH350/400 |
| First Gear Ratio | 2.43 |
| Clutch Hub | Billet steel |
| Transmission Case Style | OEM |
| Transmission Case Material | Aluminum |
| Transmission Case Finish | Black |
| Transmission Shield Built In | No |
| Flexplate Shield Built In | No |
| Fluid Fill Location | Case |
| Transmission Fluid Included | Yes |
| Transmission Fluid Quantity Included | 12 qt. |
| Fluid Detail | FTI 3-gallon RacerPak performance ATF |
| Dipstick Included | Yes |
| Dipstick Detail | Locking dipstick and tube |
| SFI Rating | SFI 4.1/30.1 |
| Remanufactured | Yes |
| Quantity | Sold as a kit |
| Level 4 Features | 34-element intermediate sprag, performance clutches and steels, high-flow pump, race-prepped stock case, deep aluminum pan, billet forward clutch hub, heavy-duty intermediate retainer, 4-clutch intermediate pack |
| Intended Use | Drag racing, weekend bracket racing, high-powered street cars, and mud trucks |
| Compatibility Support | Confirm fitment before ordering |
Ordering Support and Fitment Guidance
Before ordering the FTI Performance TH400 Level 4 Transmissions TH400-4K21, confirm that the kit matches your Chevy application, TH400 platform requirements, converter needs, flexplate setup, trans-brake wiring, cooling layout, and race safety requirements.
Important details to verify include vehicle year, make, model, engine platform, Chevy bellhousing bolt pattern, TH400 transmission compatibility, torque converter fitment, 3,400–3,800 rpm stall suitability, converter bolt pattern, crankshaft pilot fitment, flexplate compatibility, starter setup, 30-spline hardened steel TH350/400-style input shaft compatibility, slip-on/bolt-on yoke requirements, reverse shift pattern, full manual valve body operation, shifter compatibility, trans-brake wiring, cooler mounting, cooler line routing, fluid requirements, SFI 4.1/30.1 requirements, transmission mount location, crossmember position, driveshaft length, and installation hardware.
This kit includes the TH400 transmission, 3,400–3,800 rpm stall billet torque converter, trans-brake, complete cooler kit, 12 qt. of FTI performance ATF, and locking dipstick and tube.
It does not include the flexplate, does not include the transmission controller, and does not include the wiring harness.
Our team can help confirm compatibility using the TH400-4K21 part number, Chevy engine setup, converter requirements, flexplate requirements, yoke setup, shifter configuration, trans-brake wiring needs, cooling layout, SFI requirements, and drivetrain information before ordering.
Frequently Asked Questions
What is the FTI Performance TH400-4K21 transmission kit?
The FTI Performance TH400-4K21 is a 3-speed remanufactured Chevy TH400 Level 4 automatic racing transmission kit with a reverse shift pattern, full manual valve body, included trans-brake, included 3,400–3,800 rpm stall billet converter, included cooler kit, included ATF, included locking dipstick, and 900 horsepower rating.
How many gears does this transmission have?
This transmission has 3 gears.
What horsepower rating does this transmission have?
The transmission advertised horsepower rating is 900 horsepower. Buyers should confirm suitability for the exact engine output, converter, rear gear, tire size, vehicle weight, cooling system, and intended racing application.
What bellhousing bolt pattern does this transmission use?
This transmission is listed with a Chevy bellhousing bolt pattern. Buyers should confirm exact engine, converter, flexplate, starter, and vehicle compatibility before ordering.
What valve body style does this transmission use?
This transmission uses a full manual valve body, designed for driver-controlled shifting in compatible racing applications.
What shift pattern does this transmission use?
This transmission uses a reverse shift pattern.
Does this kit include a torque converter?
Yes. This kit includes a 3,400–3,800 rpm stall billet torque converter equipped with a mechanical diode and balloon plate.
Does this kit include a trans-brake?
Yes. The trans-brake is included. Buyers should confirm wiring, activation method, shifter compatibility, staging setup, and race rules before installation.
Does this kit include a transmission cooler?
Yes. This kit includes a complete cooler kit with the cooler, 15 ft. of line, hose ends, and fittings.
Does this kit include transmission fluid?
Yes. This kit includes 12 qt. of FTI performance ATF, listed as FTI’s 3-gallon RacerPak.
Does this kit include a dipstick?
Yes. This kit includes a locking dipstick and tube.
Does this kit include a flexplate?
No. The flexplate is not included. Buyers should confirm the correct flexplate for the engine, crankshaft, converter bolt pattern, balance requirement, and starter setup.
Does this kit include a controller or wiring harness?
No. The transmission controller is not included, and the wiring harness is not included.
Is this transmission lockup compatible?
No. This transmission is listed as not lockup compatible.
What is the first gear ratio?
The listed first gear ratio is 2.43.
What input shaft does this transmission use?
This transmission uses a 30-spline hardened steel TH350/400-style input shaft.
What SFI rating does this transmission have?
This transmission is listed with an SFI 4.1/30.1 rating.
Is this transmission remanufactured?
Yes. This transmission is listed as remanufactured.
Who is this transmission kit best for?
This kit is best for drag racers, weekend bracket racers, mud truck builders, high-powered street car owners, race teams, performance shops, race-prep garages, transmission installers, and drivetrain specialists who need a compatible FTI TH400 Level 4 transmission kit with trans-brake, converter, cooler kit, ATF, locking dipstick, and 900 horsepower rating.
Reviews
There are no reviews yet.