Understanding the 396 Boreshop Complete Rebuild Kit

The 396 Boreshop Complete Rebuild Kit is a comprehensive package engineered for classic car owners and performance enthusiasts who demand a full engine restoration. Unlike partial rebuild kits, this set includes every wear component needed to return a big-block Chevrolet 396 to factory specifications or better. Each kit is assembled with meticulous attention to material quality, ensuring that the bearings, rings, gaskets, and timing components meet or exceed OEM tolerances.

The kit typically covers the rotating assembly and sealing surfaces. Key components include:

  • Main and rod bearings – tri-metal or bi-metal options for durability under high loads
  • Piston rings – moly or chrome-faced for reduced friction and improved oil control
  • Full gasket set – including head gaskets, intake/exhaust manifold gaskets, valve cover gaskets, oil pan gasket, and timing cover gasket
  • Timing chain and gears – double-roller type for precise cam timing
  • Oil pump and pickup – high-volume or standard flow depending on the kit variant
  • Freeze plugs and cam bearings – often included to complete the short block rebuild
  • Piston pins and retainers – matched to the rings and pistons

Some kits also include a camshaft, lifters, and pushrods for a top-end refresh. The 396 Boreshop Complete Rebuild Kit is intended for engines that have been pulled, fully disassembled, and honed or bored. It does not include pistons or the crankshaft itself unless specified in a “master” kit. Enthusiasts often pair it with new cylinder heads or a performance cam for a substantial power increase.

For more details on component compatibility and manufacturer specifications, refer to Boreshop’s official kit page.

Cost Breakdown and Budgeting

The total investment for a 396 rebuild depends on whether you perform the labor yourself or hire a professional shop. The kit itself ranges from $1,200 to $2,000 depending on the component quality (e.g., standard versus high-performance bearings and rings). Beyond the kit, you should budget for machine work, tools, fluids, and unexpected parts replacement.

Kit Price Tiers

  • Standard rebuild kit – $1,200–$1,500, using OEM-grade bearings and cast-iron rings
  • Performance rebuild kit – $1,500–$1,800, featuring moly rings, tri-metal bearings, and a double-roller timing set
  • Master rebuild kit – $1,800–$2,200, often includes pistons, camshaft, and lifters for a complete long-block rebuild

Additional Expenses

  • Machine shop services (bore/hone, line bore, decking, crank polish/grind): $400–$900
  • Professional labor (if not DIY): $800–$1,500, potentially more for complex installations
  • Specialty tools (ring compressor, torque angle gauge, dial bore gauge): $100–$300
  • Fluids and filters (break-in oil, coolant, assembly lube, oil filter, fuel filter): $80–$150
  • New fasteners (head bolts, rod bolts, main cap bolts): $50–$120
  • Nitrous or forced induction preparation: often adds $300–$600 if you upgrade to forged or coated components

Overall, a meticulous DIY rebuild with a standard kit and basic machine work typically lands between $2,200 and $3,000. A shop-performed rebuild starting with a master kit can exceed $5,000. Always keep a contingency fund of 10–15% for broken bolts, damaged cylinder walls, or hidden casting flaws.

Preparing for the Rebuild

Successful engine rebuilding hinges on thorough preparation. Before you pull the engine, arrange your workspace and gather the correct tools.

Essential Tools

  • Engine hoist (2-ton capacity) and load leveler
  • Engine stand (capable of supporting the 396’s approximate 680 lb weight)
  • Full socket set (SAE and metric, with deep wells)
  • Torque wrench (ft-lb and in-lb ranges)
  • Piston ring compressor (adjustable, for 4.094–4.250 bore)
  • Feeler gauges and plastigauge
  • Dial indicator and magnetic base
  • Micrometer and bore gauge (or have machine shop measure)
  • Clean rags, degreaser, and parts washer
  • Magnetic parts tray and labeled bags

Workspace Requirements

Work in a clean, well-lit area with concrete flooring. Cover the floor with cardboard or old carpet to catch drips. Ensure you have adequate ventilation if using chemical cleaners. Reserve a large bench or table for disassembly and organization. Label every component group (e.g., “front cover bolts,” “intake manifold bolts”) to avoid confusion during reassembly.

Safety First

Always disconnect the battery before working on the vehicle. Use jack stands or a lift rated for the car’s weight. Wear safety glasses and gloves when handling solvents and metal parts. Never work under a vehicle supported only by a floor jack. For engine removal, have a helper guide the hoist and load leveler. The 396 is heavy and can shift unexpectedly.

Step-by-Step Installation Process

The rebuild process is divided into six major stages. Take your time; rushing leads to mistakes that can destroy the engine on startup.

Step 1: Remove the Old Engine

  1. Disconnect the battery negative terminal.
  2. Drain the coolant, engine oil, and transmission fluid if the trans is attached.
  3. Disconnect all electrical connectors, fuel lines, and vacuum hoses. Label each.
  4. Remove the radiator, fan, and shroud for clearance.
  5. Unbolt the exhaust manifolds or headers from the cylinder heads.
  6. Disconnect the torque converter or clutch linkages.
  7. Unbolt the engine mounts from the block or subframe.
  8. Attach the engine hoist with a leveler, lift slightly to take tension, then remove the crossmember or K-member if needed.
  9. Carefully lift the engine out while watching for clearance on the firewall and transmission tunnel.

Step 2: Disassemble the Engine

Place the engine on a stand. Drain any residual oil. Remove the following in order:

  1. Intake manifold and carburetor/throttle body
  2. Valve covers, rocker arms, pushrods, and cylinder heads
  3. Timing cover, timing chain, and camshaft (note: align timing marks before removal)
  4. Oil pan, oil pump, and pickup tube
  5. Pistons and connecting rods – mark their cylinder positions
  6. Main bearing caps and crankshaft – store caps with their original positions
  7. Cam bearings (if replacing) and freeze plugs

Keep all original fasteners sorted. Photograph the disassembly sequence for reference.

Step 3: Clean and Inspect Parts

Take the block and cylinder heads to a trusted machine shop for hot-tanking or ultrasonic cleaning. At home, scrub all iron and steel parts with solvent and a wire brush. Inspect the block for cracks (use a magnetic particle or pressure test), cylinder wall taper, and main bearing bore alignment. Check the crankshaft for journal wear and straightness. Replace any oil galley plugs. Only proceed if the block is within serviceable limits.

Step 4: Install New Components from the Kit

After machine work is complete (bore/hone, deck, line bore, etc.), begin assembly with the short block:

  • Cam bearings – install with a tool that aligns the oil holes. Lubricate with cam lube.
  • Freeze plugs – apply a thin coat of sealer and tap in evenly.
  • Crankshaft – install main bearings with lubrication, set the crank, align thrust bearing, torque main caps to spec (typically 95–110 ft-lb for 396s).
  • Pistons and rods – file-fit rings if needed, compress rings, insert assembled piston/rod into cylinder with a ring compressor. Torque rod bolts to spec (using torque angle if specified).
  • Timing set – align cam and crank timing marks at top dead center, install chain and gears, torque cam bolt to 65–75 ft-lb.
  • Oil pump – pack with assembly lube, install with pickup, torque bolts to 65 in-lb.
  • Oil pan – use the new gasket, apply silicone at corners, torque in sequence (around 10–12 ft-lb).

Continue with the top end: install cylinder heads with new head gaskets (torque in three steps to factory spec, often 70–90 ft-lb), pushrods, rocker arms, and adjust valve lash. Finally, mount the intake manifold and timing cover with new gaskets. Always follow the torque sequences specified in a factory service manual or rebuild guide from Summit Racing.

Step 5: Reassemble the Engine

Reverse the disassembly steps, installing the valvetrain, intake, exhaust manifolds, distributor, water pump, and all accessories. Use new gaskets throughout. Fill the engine with break-in oil (non-synthetic, high-zinc). Prime the oil system by rotating the oil pump shaft with a drill until oil reaches the valvetrain.

Step 6: Reinstall the Engine

Lower the engine into the engine bay using the hoist and leveler. Align the engine mounts and transmission input shaft. Bolt the mounts, reconnect the exhaust, cooling system, fuel lines, and wiring. Refill coolant, connect the battery, and check for leaks before startup.

Performance Results and Dyno Testing

After a proper rebuild with the 396 Boreshop Complete Rebuild Kit, owners consistently report substantial gains. A stock 396 from the late 1960s typically produced 325–375 horsepower. With a rebuild restoring compression and sealing, a baseline dyno run may show 300–340 horsepower at the wheels (depending on drivetrain loss).

Upgraded kits with moly rings, performance bearings, and a mild cam can push wheel horsepower to 400–450. Combined with ported cylinder heads and a matching intake, some builders have seen over 500 horsepower. Torque improves similarly, with peak torque often rising by 40–70 lb-ft and the curve shifting lower in the RPM range.

  • Horsepower gain: 30–80+ hp (depending on prior wear and upgrades)
  • Torque gain: 40–100 lb-ft
  • Fuel efficiency: 1–3 mpg improvement due to better ring seal and reduced friction
  • Idle quality: smoother, more stable vacuum reading
  • Oil consumption: near zero after break-in, versus up to 1 quart per 500 miles on a worn engine

For real-world testimonials, check forums like Chevellestalk where users share before/after dyno sheets.

Engine Break-In and Post-Installation Care

Proper break-in is critical to seat the piston rings and ensure long engine life. Follow these guidelines:

  1. Start the engine and immediately bring idle to 2,000–2,500 RPM. Do not let it idle below 1,500 RPM for the first 20 minutes.
  2. Check for oil pressure, coolant temperature, and any leaks.
  3. After 20 minutes, allow the engine to cool. Retorque the cylinder head bolts (if using conventional head gaskets).
  4. Change the oil and filter after the first heat cycle.
  5. Drive gently for the first 500 miles. Vary engine speed; do not maintain constant RPM for long periods. Avoid wide-open throttle and high RPM.
  6. After 500 miles, perform another oil and filter change. Inspect the oil for metal particles.
  7. After 1,000 miles, the engine can be driven normally. A final oil change with full synthetic is optional.

Use high-zinc break-in oil (ZDDP level of 1,200–1,800 ppm) to protect flat-tappet camshafts. After break-in, switch to a quality conventional oil with adequate ZDDP or use an additive.

Frequently Asked Questions

Is the 396 Boreshop Complete Rebuild Kit compatible with all 396 variants?

Yes, the kit is designed for standard-bore 396 blocks (4.094-inch bore). If your block has been bored oversize (0.030, 0.060), order the corresponding ring and piston sizes separately. Confirm crankshaft journal dimensions – some marine or tall-deck variants differ.

Can I reuse my old pistons?

If the pistons are in good condition and within tolerance, you can reuse them with new rings. However, most rebuilders replace pistons if the block is bored oversize or if the skirt coatings are worn.

How long does a full rebuild take?

For a first-time builder, plan on 40–60 hours of labor spread over several weekends. An experienced mechanic can complete the job in 20–30 hours. Machine shop turnaround adds 1–3 weeks.

Do I need to upgrade the oiling system?

For street use, the standard oil pump is sufficient. For high-RPM or high-mileage builds, a high-volume pump improves oil flow to bearing surfaces.

Conclusion

Rebuilding a 396 with the Boreshop Complete Rebuild Kit is one of the most satisfying projects a car enthusiast can undertake. The cost is manageable when balanced against the reward of a fresh, powerful engine that delivers decades of reliable service. By carefully budgeting for machine work and tools, following a meticulous assembly process, and adhering to break-in procedures, you can expect remarkable performance gains and smooth operation. Whether you are resurrecting a classic Chevelle, Camaro, or truck, this kit provides everything needed to bring your big-block back to life.

For additional resources, consult the Boreshop rebuild guide and the detailed torque specifications available from Engine Builder Magazine.