A 350 long block is a complete engine assembly minus the external accessories

A 350 long block is a Chevrolet 350 cubic-inch V8 engine that includes the block, cylinder heads, crankshaft, pistons, and internal gaskets — but not the carburetor, intake manifold, alternator, water pump, or other bolt-on parts. You receive a fully assembled, running engine that needs those external components transferred from your old engine or purchased separately.

The term "long block" distinguishes it from a "short block," which contains only the block, crankshaft, and pistons without the cylinder heads. It also differs from a "crate engine," which arrives with most accessories already installed and ready to bolt in. For vehicle owners replacing a failed 350, a long block offers a middle ground: less work than rebuilding from scratch, but more assembly than a turnkey crate engine.

The 350 became Chevrolet's workhorse V8 from 1967 through the early 2000s, so long blocks are widely available used and new. Availability and cost vary significantly based on whether you buy a remanufactured unit (rebuilt to factory specs), a used takeout (pulled from a salvage vehicle), or a new reproduction.

Key Takeaways

  • A 350 long block includes the engine block, heads, and internal parts but requires you to transfer or buy the carburetor, intake manifold, alternator, water pump, and other external components.
  • Remanufactured 350 long blocks typically cost between $1,200 and $2,500, while used takeouts range from $400 to $1,000 depending on mileage and condition.
  • Installation labor usually runs 8 to 16 hours at a shop, which translates to $800 to $2,400 in labor depending on your vehicle and local rates.
  • You will need to transfer your old engine's accessories to the new long block or source replacements, adding $300 to $800 to the total project cost.
  • A long block makes sense if your original engine is seized, cracked, or has internal damage that costs more to repair than the long block itself.

New, remanufactured, and used 350 long blocks have different price ranges and guarantees

A remanufactured 350 long block is disassembled, cleaned, inspected, and reassembled to factory specifications by a machine shop or engine rebuilder. These typically carry a one- to three-year warranty and cost $1,200 to $2,500 depending on the rebuilder's reputation and whether the block was bored or honed. Remanufactured blocks are the safest choice if you need predictable performance and don't want to gamble on hidden wear.

A used takeout 350 long block is pulled from a salvage vehicle, tested to run, and sold as-is with little or no warranty. Prices range from $400 to $1,000 based on mileage, compression numbers, and the salvage yard's testing. These are cheaper but carry real risk: you may discover internal damage after installation, and most salvage yards will not accept returns once the engine leaves the lot.

A new reproduction 350 long block is manufactured to original specifications by companies like Chevrolet Performance or aftermarket builders. These cost $2,500 to $4,500 and come with full warranties. New blocks are rare for the 350 because demand is lower than for modern engines, so you will find fewer options and longer lead times.

Installation labor and accessory transfer add significant cost to the long block price

Installing a 350 long block is not a bolt-in job. A shop will charge 8 to 16 hours of labor depending on your vehicle's engine bay layout, whether the old engine is still in place, and how many accessories need transfer. At typical shop rates of $100 to $150 per hour, expect $800 to $2,400 in labor alone. Some shops charge a flat rate for 350 swaps if they do them regularly; ask for a quote before you commit.

You must also transfer or replace external components: the carburetor or fuel injection system, intake manifold, exhaust manifolds, alternator, water pump, thermostat housing, oil pan, and engine mounts. If these parts are in good condition on your old engine, transfer costs are mainly labor — perhaps $200 to $400. If they are worn or corroded, you will buy replacements at $300 to $800 depending on whether you choose OEM or aftermarket parts.

Some shops bundle labor and parts into a flat-rate swap price. Others bill separately. Get a written estimate that breaks down labor, parts, and any machine work (like honing the block or resurfacing the heads) before you authorize the work.

Decide between a long block swap and engine repair based on damage and cost

A long block swap makes financial sense when your engine has internal damage that costs more to repair than the long block itself. A cracked block, scored cylinder walls, or a seized crankshaft usually requires a full rebuild, which can cost $2,000 to $4,000 in parts and labor. A remanufactured long block at $1,500 plus $1,200 in installation labor ($2,700 total) is often cheaper and faster.

A long block swap does not make sense for external failures. A failed water pump, alternator, or head gasket should be repaired or replaced on your existing engine — these jobs cost $300 to $1,200 and take a day or two. Swapping the entire engine for an external problem wastes money.

Get a diagnostic from a shop before you decide. A compression test, borescope inspection, or oil analysis can tell you whether the damage is internal or external. If the shop cannot pinpoint the problem, ask them to estimate both repair and replacement costs so you can compare.

Sourcing a 350 long block from salvage yards, rebuilders, or online retailers

Local salvage yards are the fastest source for used takeout 350 long blocks. Call ahead with your vehicle's year and model so they can check inventory and run a compression test while you wait. Expect to pick up the engine the same day or within a few days. Prices are lowest here, but selection varies week to week.

Engine rebuilders and machine shops sell remanufactured 350 long blocks with warranties and can often install them if you bring your vehicle in. These shops are regional; search online for "350 engine rebuild near me" or ask your local mechanic for a referral. Lead times are typically two to four weeks.

Online retailers like Summit Racing, Jegs, and eBay Motors sell new and remanufactured 350 long blocks with shipping. Shipping costs $200 to $500 depending on weight and distance. You will need to arrange delivery to a local shop for installation, which adds coordination but gives you time to compare prices across multiple sellers.

Verify the 350 long block matches your vehicle's year and process

Not all 350 long blocks are identical. The 350 was produced in different versions for different vehicles and years, with variations in bore, stroke, casting numbers, and internal components. A 350 from a 1970s Chevrolet truck may not bolt directly into a 1980s Camaro without adapter work.

Before you buy, confirm the long block's casting numbers and compare them to your vehicle's original engine. The casting numbers are stamped on the block and cylinder heads; a machine shop or rebuilder can decode them and tell you whether the block is correct for your process. If the block is from a different year or vehicle, ask the seller whether adapters or modifications are needed.

Also verify that the long block uses the same bolt pattern for engine mounts, exhaust manifolds, and intake manifold as your vehicle. Mismatches require custom fabrication, which adds $500 to $1,500 in labor and parts.

Frequently Asked Questions

Can I install a 350 long block myself if I have basic mechanical skills?

A 350 long block swap requires engine hoist, engine stand, torque wrench, and gasket scrapers — tools most home mechanics do not own. The job involves breaking engine mounts, disconnecting fuel and coolant lines, and aligning the engine precisely. Most people should have a shop do this work. If you are experienced, budget 20 to 30 hours and rent or buy the specialized tools.

What warranty comes with a remanufactured 350 long block?

Remanufactured blocks typically carry one- to three-year warranties covering internal defects like bearing wear or piston failure. Warranties do not cover installation damage, external component failure, or damage from improper maintenance. Read the warranty document before you buy; some rebuilders offer longer coverage for a higher price.

How long does a 350 long block last after installation?

A remanufactured 350 long block should last 100,000 to 150,000 miles if maintained with regular oil changes and proper cooling. A used takeout block depends entirely on its previous history and mileage; it may last 50,000 miles or 150,000 miles. Maintenance matters more than the block itself — neglecting oil changes will shorten any engine's life.

Do I need to change the transmission when I install a 350 long block?

No, unless your original transmission is also failing. A 350 long block is mechanically compatible with the transmission already in your vehicle. If your transmission is slipping or leaking, repair or replace it separately based on its condition and cost.

What if the 350 long block does not start after installation?

Check fuel delivery, spark, and compression first — these are the three things an engine needs to run. Verify the carburetor or fuel injector is delivering fuel, the ignition system is firing, and the starter is turning the engine over. Most no-start problems after a swap are electrical connections or fuel system issues, not the long block itself. A shop can diagnose this in an hour or two.