*excludes Alaska, Hawaii & Puerto Rico

12.9 LT LSA Transmission Flywheel Bolts Set Flexplate Kit Crankshaft LT1

In stock
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LT and LSA Flexplate/Flywheel Bolts Set

Compatible with: GM LT series (Gen V) and LSA engines with 8 bolt crankshafts (manual and automatic transmission)

  • M11-1.5 thread, 23.5mm length (OEM length, measured underneath head)
  • Package Includes: 8 bolts
  • 12.9 high strength bolts (factory bolts are 10.9 rated)

*LS1, LS2, LS3, LS6, and LS7 engines use 6 bolt Crankshafts (part number 551926) *LS9 engines require 9 bolt Crankshafts
Also compatible with RPO codes: LT1, LT4, LT5, L83, L84, L86, L87, LV3

More Information

Bullet Point 1 Heavy duty bolts
Bullet Point 2 High strength, grade 12.9 bolts
Bullet Point 3 BP coated for long lasting corrosion protection and prevents threads from seizing
Bullet Point 4 No washers needed with these flange head bolts
Manufacturer Part Number 551939
UPC 657814753327
Weight 0.572000
ICT Manufacturer ICT Billet
United States Unknown or Varies
Length Inches 1
Width Inches 3
Height Inches 3
Download .PDF for Vehicle No

WARNING - This product can expose you to chemicals including nickel, which is known to the State of California to cause cancer, birth defects, or other reproductive harm. For more information go to


ALUMINUM: Most of the aluminum alloys used today contain some level of lead, usually less than .1%. Lead is known to the state of California to cause cancer and reproductive harm. Most aluminum alloys are physiologically inert in their solid form, and the lead is contained within, however user-generated dust and/or fumes may pose a hazard if inhaled or ingested. Heating beyond a certain temperature may also provide avenues for exposure.


STEEL (steel bolts):  Steel is an iron alloy with several metals including Nickel and Chromium. Both Nickel and Chromium are known to the State of California to cause cancer and reproductive harm, respectfully. This warning applies to stainless steels as well.