SFI-Approved Flexplate GM LS Gen III/Gen IV
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TCIPART NUMBER: 890-399853

SFI-Approved Flexplate GM LS Gen III/Gen IV

$51995
ShippingShips on Sep 03, 2026
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Chevrolet SFI 29.2 Approved Flexplates
    SFI-Approved Flexplate
  • GM LS Gen III/Gen IV
  • Laser-Welded Converter Spacers
  • Weighs 7.6 lbs

  • One-piece SFI 29.2-certified components are made from a CNC-machined 4140 forging with a hobbed-on ring gear
  • Can withstand more than 12,000 RPM
  • Gas-nitride for extra surface hardness and strength
  • Lightening holes reduce rotating mass and drop weight

    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.

Part TypeAutomatic Transmission Flexplate
Product LineTCI Heavy-Duty Flexplates
BrandTCI
Package Height1.5
Package Width15.0
Package Length15.0
Weight8.37 PG
Part CategoryPerformance Parts
Sfi-ApprovedYes
Tooth Quantity168
Engine MakeChevrolet
MaterialForged Steel
Part FitmentSemi Universal
Vendor Part Number399853
Package Qty1
Package TypeEA
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