
399753 SFI-Approved Flexplate Chevy LS1/LS6 V8 4.8/5.3/5.7/6.0L
TCI 399753 SFI-Approved Flexplate Notes:
- Will not fit 4L80-E
- Will not fit 1999-2000 6.0L with long snout crank
- Includes crankshaft bolts and pilot hub adapter for non-LS transmissions.
FAQ
What is the significance of an SFI-approved flexplate?
An SFI-approved flexplate, like the TCI 399753, ensures compliance with stringent safety standards set by the SFI Foundation. This certification guarantees the flexplate's integrity, reducing the risk of failure during high-stress situations.
What is the tooth count of the TCI 399753 flexplate?
The TCI 399753 flexplate features a 168-tooth design, providing precise engagement with the starter for reliable cranking and smooth engine operation in Chevy LS1/LS6 V8 4.8/5.3/5.7/6.0L applications.
Why is internal engine balance important for a flexplate?
Internal engine balance in the TCI 399753 flexplate ensures proper harmonics, reducing vibrations and enhancing the overall stability of the drivetrain. This design promotes smoother engine performance and improved longevity.
SFI-Approved Racing Flexplates
TCI Heavy-Duty Flexplates are .0350 in. thicker than stock plates in order to withstand the stress of high-RPM engines and high-stall torque converters. Chevy 168-tooth plates have dual bolt patterns to accommodate both Powerglide and Turbo-Hydramatic (TH) torque converters. TCI also offers externally-balanced Small Block Ford to GM Transmission Adapter Flexplates that feature a built-in pilot adapter and a dual bolt pattern for a simple bolt-on installation. Note: For use with a racing converter or GM Powerglide adapter.
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When your build demands strength, durability, and reliable performance under fire, the TCI Heavy-Duty Flexplates deliver exactly that. These heavy-duty components are built to last, especially for high-stall torque converters and high-RPM engines.
TCI flexplate models are thicker than stock—specifically .0350 inches extra—to resist warping, cracking, or damaging deflection when torque and revs rise. Chevy 168-tooth plates in this line feature dual bolt patterns so they work with both Powerglide and Turbo-Hydramatic transmissions. These plates are precision engineered to maintain alignment, retain structural integrity, and handle the stresses OEM parts can’t reliably overcome.
If you’re running an LS swap or high output small block, a TCI LS1 Flexplate option gives you a bolt-on upgrade with improved durability, especially if you’ve upgraded torque converter size, stall speed, or intend to push rev limits. Compatibility across various bolt patterns, balanced designs, and high-quality materials mean you can upgrade without compromising fitment or strength.
A chevy flex plate from this line isn’t just about brute force—it’s about maintaining reliability under load. Proper flexplate selection protects your torque converter, starter, crank flange, and ultimately your transmission. Whether for racing, high performance street, or demanding duty, using a heavy-duty version pays in longer life, fewer failures, and cleaner engagement. Add a Heavy-Duty Flexplate to your setup to get the peace of mind and performance your drivetrain deserves.



![Heavy-Duty SFI Flexplate for 1997-2016 GM LS1, LS2, LS6 Series Engines [Internally Balanced]](https://www.jegs.com/images/mini_200/500/555/555-601080.jpg)






![Flexplate [GM LS Engine]](https://www.jegs.com/images/mini_200/800/809/809-19260102.jpg)


