A Chevy 350 short block is the lower half of a V8 engine, assembled and ready to bolt into your vehicle
A short block is a partially assembled engine that includes the block itself, crankshaft, pistons, connecting rods, and camshaft — everything below the cylinder head. When you buy a Chevy 350 short block, you are getting a core engine unit that runs on its own but still needs the top end (cylinder heads, intake manifold, valve covers) installed before it will start. This matters because a short block costs significantly less than a complete engine and lets you reuse your existing heads and accessories if they are in good condition.
The 350 refers to the engine's displacement: 350 cubic inches, or about 5.7 liters. Chevrolet produced 350 engines from 1967 through the early 2000s across multiple generations, so a short block can come from any of those eras depending on what you order. The year and generation matter because bolt patterns, oil passages, and internal dimensions changed over time, and you need to match the short block to your vehicle's year and the heads you plan to use.
Key Takeaways
- A short block includes the engine block, crankshaft, pistons, connecting rods, and camshaft, but not the cylinder heads or any external accessories.
- You must verify the year and generation of the short block you buy, because 350 engines from different decades have different bolt patterns and internal specifications.
- A short block is cheaper than a complete crate engine but requires you to transfer or purchase cylinder heads, intake manifold, alternator, water pump, and other top-end parts.
- New short blocks are more expensive than rebuilt or used ones, but come with a warranty and known internal condition.
What parts are included in a 350 short block
The short block itself is the engine block — the iron or aluminum casting that holds the cylinders, oil passages, and coolant galleries. Inside it sits the crankshaft, which converts the up-and-down motion of the pistons into rotational motion that turns the wheels. The pistons and connecting rods link the crankshaft to the cylinders and move up and down as fuel burns. The camshaft opens and closes the intake and exhaust valves at the right moment in the engine cycle.
Most short blocks also come with the oil pan bolted to the bottom, the timing cover at the front, and sometimes the water pump and thermostat housing. Some sellers include the harmonic balancer (the large wheel at the front of the crankshaft) and the flywheel or flexplate (which connects to the transmission). Always ask the seller what is bolted on and what you need to source separately, because this varies between vendors and can add hundreds of dollars to your total cost.
What you still need to buy to make it run
The most critical missing piece is the cylinder head or heads — the casting that bolts on top of the block and contains the valves, spark plug holes, and combustion chambers. You need two heads for a 350 (one per side). If your old heads are still good, you can have them cleaned and resurfaced and bolt them back on. If not, you will need to buy new or rebuilt heads, which can cost $400 to $1,500 per head depending on quality and whether they are bare castings or come with valves and springs already installed.
You also need an intake manifold (the passage that delivers fuel and air to the cylinders), exhaust manifolds or headers, valve covers, alternator, water pump (if not included), fuel pump, distributor or ignition coil pack (depending on the year), spark plugs, belts and hoses, and gaskets and seals throughout. If you are reusing parts from your old engine, you can transfer them over. If you are building from scratch, budget $1,500 to $3,000 for these components on top of the short block cost.
New versus rebuilt short blocks
A new short block is manufactured by Chevrolet or a licensed rebuilder and has never been run. It comes with a warranty (usually 12 months or 12,000 miles) and a known internal condition. New blocks are the most expensive option, typically $2,500 to $4,500, but they carry the lowest risk of hidden wear or defects.
A rebuilt short block is a used engine that has been disassembled, inspected, and reassembled with new or reconditioned internal parts. The block itself is reused, but the crankshaft, pistons, and bearings are replaced or resurfaced. Rebuilt blocks cost $1,200 to $2,500 and usually come with a 12-month warranty. The risk is lower than buying a used block outright, but higher than new because you are trusting the rebuilder's inspection process.
A used short block is pulled from a junkyard or salvage yard and sold as-is with no warranty. These cost $400 to $1,200 but carry the highest risk — you do not know the mileage, maintenance history, or whether internal wear will cause failure soon after installation. Many people buy used blocks only if they can inspect them in person or have a trusted mechanic check them before purchase.
Matching the short block to your vehicle and heads
The year of the short block matters because Chevrolet changed the bolt pattern, oil passage locations, and internal geometry across generations. A 350 from 1970 will not bolt directly to heads from a 1990 engine without adapters, and even then you may have cooling or oil flow problems. Before you buy, confirm the year of your vehicle and the year range of the short block you are considering.
The block casting number — stamped on the side of the block — tells you the exact year and sometimes the original process (truck, car, performance). You can look this up online or ask the seller to provide it. If you are reusing your old heads, bring the casting number of your heads to the seller and ask if they are compatible with the short block you want to buy. If you are buying new heads, make sure they are designed for the same generation of block.
Some 350 blocks are two-bolt main (older, less rigid) and some are four-bolt main (newer, stronger). If you plan to build a high-performance engine, a four-bolt block is preferable, but it will cost more. For a stock rebuild or mild performance use, a two-bolt block is fine.
Installation and machine work
Installing a short block is not a bolt-on job for most people. You will need to remove your old engine, which requires disconnecting the transmission, cooling system, fuel system, and wiring harness. The short block then bolts into the engine bay in place of the old one. If you are not experienced with engine work, this is a job for a machine shop or experienced mechanic — expect to pay $800 to $1,500 in labor.
Before installation, many shops will hone the cylinders (smooth the walls to accept new piston rings) and balance the rotating assembly (crankshaft, pistons, and rods) to reduce vibration. These steps add $300 to $600 but improve reliability and longevity. If you are buying a new short block, honing may not be necessary, but a used or rebuilt block often benefits from it.
Where to buy a Chevy 350 short block
New short blocks are available from Chevrolet dealerships (though they may special-order them), engine rebuilders like Jasper Engines or Edelbrock, and online retailers that specialize in crate engines. Rebuilt blocks come from local machine shops, national rebuilders, and eBay or Craigslist sellers. Used blocks are found at salvage yards, online marketplaces, and local classifieds.
When shopping, get a written description of what is included, ask about the warranty, and confirm the casting number and year. If buying used or rebuilt, ask whether the block has been pressure-tested (to check for cracks) and whether the cylinders have been bored or honed. Request photos of the block interior if you cannot inspect it in person. Shipping a short block costs $200 to $400 depending on distance, so factor that into your total cost.
Frequently Asked Questions
Can I use a 350 short block from a truck in a car?
Yes, if the year and generation match. A 1985 truck 350 will bolt into a 1985 car 350 engine bay because the block dimensions and bolt patterns are the same. However, a 1970 truck 350 and a 1990 car 350 are not interchangeable without significant modification. Always confirm the year of both your vehicle and the short block before buying.
How long does a rebuilt short block last?
A properly rebuilt short block with quality internal parts can last 100,000 to 200,000 miles if maintained well. Life depends on the rebuilder's standards, how hard you drive the engine, and whether you change the oil regularly. New short blocks typically last longer because the internal components have no prior wear.
Do I need to break in a new or rebuilt short block?
Yes. New and rebuilt short blocks require a break-in period of 500 to 1,000 miles where you avoid sustained high RPMs and heavy load. This allows the piston rings to seat properly against the cylinder walls. Follow the rebuilder's or manufacturer's break-in instructions, as they vary.
What is the difference between a short block and a long block?
A short block stops at the cylinder head mounting surface. A long block includes the cylinder heads, intake manifold, and sometimes the valve covers and accessories. A long block is more expensive but requires less additional work to install.
Can I bore a 350 short block to a larger displacement?
Yes, but only to a certain limit. A 350 can typically be bored 0.030 to 0.060 inches over its original size, which increases displacement slightly. Boring beyond that risks thin cylinder walls and overheating. This work must be done by a machine shop before you assemble the engine, and it adds $300 to $600 to your cost.