Stock replacement rebuild kit
Use this when you want to refresh a mostly stock LS engine with the normal wear parts replaced. This path is best for engines staying close to factory power levels.
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Premade Refresh Kit
Choose Each Part
1997-2003 1st Design
2007+ 2nd Design
Measuring
Measuring
Clearance
Measuring
Assembly
Assembly
Teardown
Teardown
Teardown
Front Drive
Front Drive
Pistons
Pistons
Cleaning
Cleaning
Cleaning
Supplies
Supplies
Supplies
Supplies
Machine Work
Short Block
Long Block
Rebuild kit
Choose your LS rebuild path.
Start by understanding how the engine comes apart, how machine-shop measurements affect parts selection, and when a stock refresh kit makes sense. Then choose either a premade stock refresh kit or build your own rebuild kit one part at a time.
Block Wear And Machine Shops
Champ Motorsports professional opinion on rebuilding junkyard engines
If you are buying an engine with known history and you are only doing a mild refresh, you can often keep the rebuild simple. In that case, checking crank-to-main-bearing oil clearance with Plastigage, inspecting the cylinder walls, and confirming there are no obvious wear problems may be enough for a budget-friendly build.
If you do not know the engine's history, the engine has more than 100,000 miles, or you are planning a higher-horsepower build that you want to last another 150,000 miles or more, a machine shop inspection is worth the money. The shop can measure the block, cylinder bores, and crank journals correctly, then tell you whether the cylinders need to be honed or bored, whether the crank needs work, and which pistons, rings, and bearings match the final measurements.
Machine shops can also handle jobs that require expensive specialty tools, like replacing cam bearings, and they already have the measuring tools needed to inspect the block correctly. Our recommendation is simple: if the engine is unknown, high-mileage, or being built for serious power, do not guess on oversized parts. Let the machine shop measure the engine first, then buy the parts that match the machined block and crank.
Choose Your Rebuild Path
Pick a premade stock refresh kit or choose each rebuild part.
This keeps the first rebuild decision simple: one kit for a basic refresh, or the full checklist for builders who need machine-shop sizing, upgraded parts, or more control over each item.
Build your own rebuild kit
Use this when you want upgraded parts beyond a basic stock refresh, organized into a compiled checklist of LS rebuild parts that can be replaced, reused, or selected after machine-shop sizing.
Open parts checklistCam Bearings
Cam bearing options for a stock refresh.
Stock rebuild kits do not always include cam bearings. LS cam bearings are based on block design, so confirm the block year, casting number, and cam bearing position 1 and 5 housing bore before ordering.
Dura-Bond CHP-10T LS cam bearing set
Fits 1997-2003 1st Design GM LS blocks where cam bearing positions 1 and 5 housing bores measure 2.3260"-2.3280". Verify the exact block before ordering.
View itemCH-25 LS cam bearing set
Fits 2007 and newer GM LS blocks where positions 1 and 5 measure 2.3460"-2.3480". Certain 2003-2006 LS blocks that call for CH-23 may also use CHP-25 or CH-25 style bearings after measurement.
View itemComplete Rebuild Videos
Watch how an LS engine comes apart and goes back together.
Use these videos to understand teardown, short block assembly, and long block assembly before choosing rebuild tools or ordering parts.
5.3 LS teardown walkthrough
This teardown focuses on a 5.3, but most Gen III LS engines share enough layout that it is a strong starting point for learning how the engine comes apart.
LS short block assembly
A short block walkthrough covering the rotating assembly, main caps, bearings, and the foundation of the engine before the top end goes on.
Note: this build uses ARP main cap bolts. ARP fasteners are aftermarket and can use a different torque sequence or torque specification than stock GM bolts, so always follow the fastener manufacturer's instructions for the exact hardware being installed.
LS long block assembly
A long block walkthrough covering cylinder heads, valvetrain parts, timing components, and the pieces that turn the short block into a complete engine assembly.
Rebuild tools
Tools needed for an LS rebuild.
These tools help with teardown, measuring, cleaning, and final assembly. Some machine shops can handle measuring and cam bearing work for you, but these are the main tools to understand before rebuilding an LS at home.
Micrometers
Used to measure crank journals and other precision engine parts before choosing bearings or confirming machine-shop measurements.
View itemDial bore gauge
Used with micrometers to check cylinder bore size, taper, and out-of-round before choosing pistons, rings, or machine-shop work.
View itemPlastigage
Helpful for checking crank-to-bearing oil clearance during a beginner-friendly rebuild.
View itemFeeler gauges
Useful for checking small gaps during engine assembly, including ring gap checks and general clearance work.
View item1/2-inch torque wrench and angle gauge
Needed for higher-torque LS fasteners like head bolts, main bolts, rod bolts, crank bolt steps, and other torque-to-angle hardware.
View item3/8-inch torque wrench
Useful for smaller engine assembly fasteners like valve covers, front cover, rocker arms, cam retainer plate, intake, and water pump hardware.
View itemBasic socket set
A basic mechanic socket set is needed for covers, accessories, brackets, intake parts, and general LS teardown work.
View itemImpact socket set
Impact sockets are useful for stubborn teardown hardware and are safer to use with an impact gun than chrome hand-tool sockets.
View itemImpact gun
Helpful for disassembly and stubborn bolts. Use a torque wrench for final assembly, not an impact gun.
View itemBalancer puller
Used to remove the harmonic balancer without damaging the crank snout or front seal area.
View itemBalancer installer
Used to reinstall the harmonic balancer straight and controlled without hammering it onto the crankshaft.
View item4.8 / 5.3 LS piston ring compressor
Used to install 4.8 or 5.3 LS pistons without damaging the rings or cylinder walls. Match the compressor to the bore size before ordering.
View item6.0 LS piston ring compressor
Used to install 6.0 LS pistons without damaging the rings or cylinder walls. Match the compressor size to the engine bore before ordering.
View itemEngine degreaser
Used to clean oil, grime, and buildup from the outside of the engine before teardown and from reusable parts before inspection.
View itemBrake cleaner
Used for final cleaning on metal parts, gasket surfaces, bolt holes, and oily areas before inspection or reassembly.
View itemBrush cleaning kit for LS engines
Used to clean bolt holes, oil passages, coolant passages, gasket surfaces, and tight block areas before final assembly.
View itemClevite assembly lube
Used on bearings, cam journals, lifters, pushrod tips, rocker contact points, and other parts that need protection before oil pressure builds.
View itemLoctite threadlocker
Used on fasteners that call for threadlocker so bolts stay secured through heat, vibration, and engine operation.
View itemEngine oil
Used during startup, break-in, and oiling checks after reassembly. Match the oil choice to the engine clearances, bearing setup, and break-in plan.
View itemGasket maker
Used where LS covers, corners, and sealing joints need gasket maker during reassembly. Follow the service procedure for where sealant is required.
View itemMeasure before buying oversized parts
If the block goes to a machine shop, wait for final bore size and crank measurements before buying pistons, rings, rod bearings, or main bearings.
- Why it matters
- Oversized pistons, file-fit rings, and undersize bearings must match the final machined dimensions.
Bearings and rings
Main bearings, rod bearings, cam bearings, and piston rings are the foundation of oil control, compression, and long-term engine life.
Gaskets and sealing
Head gaskets, intake gaskets, front cover gaskets, oil pan gaskets, valve seals, and rear cover seals help keep the rebuilt engine clean and reliable.
Final fitment check
Confirm the rebuild parts match your exact LS before ordering.
- Match the part path to your engine family, displacement, generation, and vehicle application.
- For high-mileage or unknown-history engines, confirm bore size and crank journal condition before choosing final sizes.
- Compare listing contents with parts already on hand so you do not duplicate gaskets, seals, or hardware.
Our Promise
Quality LS parts at a good price.
Champ Motorsports is built around dependable parts, clear LS fitment guidance, and fair pricing. Every recommendation is organized to make LS engine building easier to plan and easier to order correctly.
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