168T Flywheel Fit For Chevrolet Silverado 4.8L 5.3L 6.0L GEN III IV LS SWAP 12561680

When you're rebuilding or swapping a GEN III or GEN IV LS drivetrain, every component in the rotating assembly has to be exactly right. The flywheel is the link between your crankshaft and your starter, and getting the tooth count or bolt pattern wrong can turn a weekend project into a costly nightmare. This 168-tooth flywheel is purpose-built to OEM specification for 1999-2007 Chevrolet Silverado trucks, directly replacing GM part number 12561680 with zero compromises. This flywheel is fully compatible with Chevrolet Silverado trucks produced from 1999 through 2007 that are equipped with the 4.8L LR4, 5.3L LM7/L59/LM4, or 6.0L LQ4/LQ9 GEN III and GEN IV LS engines. These are the most prolific LS powerplants GM produced, and they share a common crankshaft flange bolt pattern and a 168-tooth ring gear specification. Whether you're doing a factory-spec rebuild on a high-mileage Silverado, refreshing a work truck drivetrain, or performing an LS swap into a custom project vehicle using a Silverado donor block, this flywheel delivers the correct tooth engagement and dimensional accuracy that professional builders and serious DIYers require. Always confirm your starter drive gear is rated for a 168-tooth ring gear and verify your crankshaft flange bolt pattern before installation. • Direct bolt-on OEM replacement for GM part number 12561680 — no grinding, no modifications, no adapter plates required • 168-tooth ring gear provides correct starter pinion engagement across all 4.8L, 5.3L, and 6.0L GEN III and GEN IV LS applications • Precision-balanced to OEM tolerances for vibration-free operation at idle and under high-RPM performance conditions • Engineered for both stock factory rebuilds and LS swap builds requiring a 168-tooth count for starter compatibility • Drop-in fitment reduces installation labor and eliminates the risk of improper fitment from using non-spec components • Covers the broadest range of popular Silverado build years, making it a go-to choice for shop inventory and fleet service • Tooth Count: 168 teeth • OEM Reference Number: GM 12561680 • Compatible Engine Families: GEN III LS (LR4, LM7, LM4, L59), GEN IV LS (LQ4, LQ9) • Engine Displacements: 4.8L, 5.3L, 6.0L • Vehicle Application: 1999-2007 Chevrolet Silverado • Ring Gear Engagement: Compatible with OEM and aftermarket 168-tooth starters • Crankshaft Flange: Matches standard GEN III/IV LS crankshaft bolt pattern • Balance: Factory OEM balance specification This flywheel is constructed from high-carbon steel, the same class of material used in OEM GM rotating assemblies. High-carbon steel provides the hardness and fatigue resistance required to handle the repeated thermal cycling, torsional stress, and starter engagement loads that a truck drivetrain generates over tens of thousands of cycles. The ring gear teeth are precision-machined with consistent tooth profile geometry to ensure reliable engagement with the starter pinion gear on every crank. The crankshaft mating surface is flat-ground to eliminate wobble and runout, which is critical for maintaining clutch disc life in manual transmission applications and for ensuring accurate TDC timing in performance builds. The overall construction meets or exceeds the dimensional standards set by the original GM specification, so you're not sacrificing durability or precision by choosing this replacement over a dealer-sourced unit. This is a component built to last the life of the engine, not just a stopgap fix. Before you begin, gather the following: flywheel installation tool or crankshaft holding tool, torque wrench capable of reaching 60 ft-lbs or higher, thread locker (medium strength), a straightedge or dial indicator for runout verification, and new flywheel bolts if yours show any thread damage. Step 1: Safely lift and support the vehicle, then remove the transmission (manual) or torque converter and automatic transmission as applicable. Step 2: Mark the orientation of the old flywheel relative to the crankshaft before removal to preserve factory balance indexing if desired. Step 3: Use a crankshaft holding tool to prevent rotation, then remove the flywheel bolts in a star pattern. Step 4: Remove the old flywheel and clean the crankshaft mating flange thoroughly, removing all rust, debris, and old thread locker residue. Step 5: Seat the new 168-tooth flywheel against the crankshaft flange, aligning the bolt holes. Step 6: Apply medium-strength thread locker to the flywheel bolts and hand-thread them in. Step 7: Torque the bolts in a star pattern to the GM specification — typically 74 ft-lbs for GEN III/IV LS applications, but always confirm with your factory service manual. Step 8: Use a dial indicator to verify flywheel runout is within 0.005 inches. Step 9: Reinstall the transmission and starter, reconnect all linkage and wiring, and verify starter engagement before returning the vehicle to service. • 1x 168-tooth flywheel (GM 12561680 replacement) At Expedite Parts, we stock the specific components LS builders and Silverado owners actually need — not watered-down generic listings that leave you guessing. Every product in our catalog is matched to real vehicle applications, and our product data is verified against OEM references so you can order with confidence. We offer fast US shipping, a straightforward returns process, and knowledgeable support for fitment questions. Whether you're wrenching in your driveway or running a commercial shop, we're here to keep your builds moving forward without delays or dead ends. Stop second-guessing flywheel specs. This 168-tooth GEN III/IV LS flywheel is the correct OEM-replacement part for your 1999-2007 Chevy Silverado 4.8L, 5.3L, or 6.0L build — confirmed by GM part number 12561680. Add it to your cart today and get your LS build back on track.