Short Block vs Long Block
Short block: The bottom end of the engine only—block, crankshaft, pistons, connecting rods. Long block: A complete engine minus external accessories—includes short block plus cylinder heads, camshaft, valve train, timing components. The difference is about $2,000–$4,000 and determines how much assembly work you're doing yourself.
What 'Short Block vs Long Block' Actually Means
When buying a crate engine or getting a rebuild quote, you'll encounter these terms. Understanding the difference matters because it dramatically affects your total cost.
Short Block Includes:
- Engine block (obviously)
- Crankshaft (installed)
- Pistons and rings (installed)
- Connecting rods (installed)
- Main bearings and rod bearings
- Camshaft (sometimes, verify before buying)
- Freeze plugs
- Oil gallery plugs
Short Block DOES NOT Include:
- Cylinder heads
- Valve train (rockers, pushrods, lifters)
- Intake manifold
- Oil pan
- Timing cover
- Water pump
- Any external accessories
Long Block Includes:
- Everything in a short block, PLUS:
- Cylinder heads (assembled with valves)
- Complete valve train (rockers, pushrods, lifters)
- Timing chain/gear set
- Timing cover
- Camshaft (if not in short block)
- Oil pan
- Valve covers
Long Block DOES NOT Include:
- Intake manifold (usually)
- Carburetor or fuel injection
- Distributor
- Alternator, power steering pump, A/C compressor
- Exhaust manifolds/headers
- Flexplate or flywheel
- Harmonic balancer (sometimes included, verify)
The gray area:
Some manufacturers include intake manifolds with long blocks, others don't. Some include oil pans, others don't. ALWAYS verify exactly what's included before buying.
I learned this the expensive way. Bought a "long block" 302 that didn't include an intake manifold or oil pan. Those parts added another $600 I hadn't budgeted. Read the fine print.
Why It Matters for Your Mustang
The short block vs long block decision affects:
Cost:
- Short block: $2,000–$4,000
- Long block: $4,000–$7,000
- Difference: About $2,000 for assembled heads and valvetrain
Labor:
- Short block: You (or your shop) assembles heads, valve train, timing components (15–30 hours)
- Long block: Bolt on accessories and drop it in (8–15 hours)
Risk:
- Short block: Assembly errors possible, valve train setup critical
- Long block: Factory-assembled, tested, less can go wrong
When short block makes sense:
- You have good cylinder heads you want to reuse
- You have specific performance heads you want to install
- You're experienced with engine assembly
- Budget is tight (save $2,000+)
- You have custom valve train components
When long block makes sense:
- You want bolt-in simplicity
- You don't have good heads
- You're not experienced with engine assembly
- You value warranty and factory assembly
- Timeline is critical (faster installation)
Real-world cost comparison for 302 Windsor:
| **Configuration** | **Engine Cost** | **Additional Parts Needed** | **Assembly Labor** | **Total Cost** |
|---|---|---|---|---|
| Short Block | $2,500–$4,000 | Heads, valve train, timing: $1,500–$3,000 | 20–30 hours: $2,200–$3,600 | $6,200–$10,600 |
| Long Block | $4,500–$7,000 | Intake, accessories: $500–$1,200 | 10–15 hours: $1,100–$1,800 | $6,100–$10,000 |
The math:
Short block appears cheaper initially, but when you add heads, valve train, and assembly labor, total costs are similar. The long block saves time and reduces assembly risk.
For 351W, add about 25% to all costs
Cost Impact
| Repair Type | Typical Cost (LA) | Labor Hours |
|---|---|---|
| Short block (302 Windsor) | $2,500–$4,000 | Engine only |
| Long block (302 Windsor) | $4,500–$7,000 | Complete engine minus accessories |
| Short block (351W) | $3,000–$5,000 | Engine only |
| Long block (351W) | $5,500–$8,500 | Complete engine minus accessories |
| Assembly labor (short block) | $2,200–$3,600 | 20–30 hours |
| Installation labor (long block) | $1,100–$1,800 | 10–15 hours |
*LA labor rates: $110–$165/hour. The short block vs long block decision affects total project cost significantly. Short blocks require additional parts (heads $800–$2,500, valve train $400–$800, timing set $80–$200, oil pan $100–$250, valve covers $60–$200) and assembly labor. Long blocks require fewer additional parts (intake $200–$600, carburetor $300–$800, distributor $100–$300, accessories $300–$700) but higher initial engine cost.
Ask me how I know these numbers.
Common Issues
Assembly Errors
Improper valve train setup, timing mistakes, gasket leaks
Missing Components
Verify what's included—manufacturers differ on accessories
Hidden Costs
Short block requires many additional parts not initially obvious
Warranty Differences
Long block warranties cover more, short block warranties exclude assembly
See This in Action
- Mustang Engine Rebuild Cost Guide
Detailed short block vs long block cost breakdowns and decision frameworks
Want to Learn More?
Download the Mustang Restoration Starter Kit (LA Edition) for:
- Complete terminology reference guide
- Cost estimation worksheets
- Pre-purchase inspection checklist
- Shop interview questions
- Project timeline planning tools
No upsells. No bait-and-switch. Just the information Dorian wishes he'd had before he bought his first project car.