Complete Engine Kits & Components

What Car Engine Parts Can You Shop at JEGS?

You can shop engine categories grouped by the job each part does in your build. Start with the category that matches your project:

• Performance crate engines for complete drop-in swaps
• Engine blocks in cast iron and aluminum
• Engine block components for prepping and finishing a bare block
• Cylinder heads for stock-replacement and high-flow builds
• Camshafts and valvetrain parts to set valve timing and lift
• Crankshafts and connecting rods for stock-stroke and stroker builds
• Engine rotating assemblies that bundle the crank, rods, and pistons
• Pistons and piston rings for setting compression and sealing the bore
• Engine bearings for main, rod, and cam journals
• Engine rebuild kits for overhauling a worn engine
• Timing components to keep the crank and cam in sync
• Oil system parts to hold steady pressure and flow

Each category has its own filters, so you can sort by engine family and size before you compare specs.

Crate Engine, Short Block or Long Block: Which Do You Need?

Pick a crate engine for a complete swap, a short block to choose your top end, or a long block for a matched top end. Crate engines arrive fully assembled, which suits you if you want the least shop time.

A short block includes the block, crank, rods, and pistons. A long block adds the cylinder heads, camshaft, and valvetrain, so you only bolt on the intake, ignition, and accessories. For a full breakdown, read the difference between a short block and a long block.

Chevrolet Performance offers a 383 stroker short block and the LQ4/LQ9 6.0L Gen III cast-iron block. Ford Performance carries Boss 302 and Boss 351 blocks, plus a 347ci Boss short block.

If you're sizing a short block to a power target, start with our guide to choosing the right short block for your horsepower goals.

How Do You Build the Rotating Assembly and Bottom End?

Start with a block rated for your power level, then match the crank, rods, pistons, and bearings to it as a set. Dart offers Big M, SHP, and LS Next blocks for builds that need more strength than a factory casting. A matched rotating assembly saves you from mixing parts with different weights, which throws off balance.

These three specs drive most of your bottom-end choices:

• Stroke sets how far each piston travels, and a longer stroke adds displacement and torque
• Bore is the cylinder diameter, and your pistons and rings must match it
• Compression ratio depends on piston dome or dish, chamber size, and gasket thickness

Before final assembly, measure bearing clearances with a bore gauge or plastic gauge strips. It's a short step that prevents spun bearings and low oil pressure later.

Which Cylinder Heads and Valvetrain Parts Match Your Goals?

Choose heads and a cam as a package, because port size, valve size, and cam lift have to work in the same rpm range. If you're new to the topic, start with what a cylinder head does.

Top-end kits take the guesswork out of matching by pairing heads with a compatible cam and related parts. Edelbrock offers the Performer RPM top-end kit for big-block applications. Dart offers the Pro 1 top-end kit if you want heads and a matched cam in one order.

Once you've picked a cam, check that your valve springs, rocker arms, and retainers are rated for its lift. Confirm pushrod length with a checking tool after the heads are torqued down. A flat-tappet cam also needs a break-in procedure on first startup, while a hydraulic roller cam doesn't.

How Do You Choose Engine Components That Fit Your Build?

Start with your vehicle, your engine family, and your power target, then filter from there. Add your vehicle in the selector at the top of the page to narrow results to parts listed for it. From there, filter by engine make, engine size, bore, compression ratio, or brand.

Your budget shapes the plan as much as your horsepower goal. If you're weighing cost against output, compare a budget vs performance engine build before you commit to parts. A stock-spec refresh can reuse your heads, while a high-output build usually calls for new heads, a new cam, and stronger internals.

Write down your bore, stroke, and deck height before you order. Those numbers decide which pistons, gaskets, and pushrods fit. Once your specs line up, add the parts to your cart and get back to building.