Complete short block replacement for the 1966 Chevrolet Corvette 327ci V8, including removal of cylinder heads, oil pan, timing cover, and all rotating assembly components, then installation of new short block and reassembly of all ancillary components.

Warnings

Tools required

Parts

• Complete short block assembly (327 V8) × 1 — Use OEM specification or aftermarket equivalent
• Cylinder head gasket set × 1 — Fel-Pro 7733PT or equivalent
• Timing cover gasket × 1 — Use OEM specification
• Oil pan gasket × 1 — Fel-Pro OS30390R or equivalent
• Intake manifold gasket set × 1 — Use OEM specification
• Exhaust manifold gaskets × 2 — Use OEM specification
• Valve cover gaskets × 2 — Use OEM specification
• Timing chain and gear set × 1 — Cloyes 9-3100 or equivalent
• Oil pump × 1 — Melling M55 or OEM equivalent
• Oil pump pickup tube and screen × 1 — Use OEM specification
• Harmonic balancer × 1 — Use OEM or reuse if serviceable
• Rear main seal × 1 — Use OEM specification
• Front timing cover seal × 1 — Use OEM specification
• Oil filter × 1 — AC Delco PF25 or equivalent
• Spark plugs × 8 — AC Delco R44 or equivalent
• Engine assembly lube × 1 — Use OEM specification
• RTV silicone sealant (high-temp) × 1 — Permatex 81160 or equivalent
• Thread locker (medium strength) × 1 — Loctite 242 or equivalent
• Anti-seize compound × 1 — Use OEM specification
• Engine oil × 2 — 5W-30 Conventional

Fluids

• 5W-30 Conventional engine oil — 5 qt
• DEX-COOL Extended Life Coolant (Orange) — 10 qt

Preparation

1. Park vehicle on level surface and engage parking brake
2. Disconnect negative battery cable
3. Drain cooling system completely by opening radiator petcock and block drain plugs
4. Drain engine oil and remove oil filter
5. Remove hood by unbolting from hinges (mark hinge position for reinstallation)
6. Remove air cleaner assembly and carburetor linkage
7. Label and disconnect all vacuum lines, fuel lines, and electrical connections from engine
8. Remove radiator, fan shroud, and fan assembly
9. Remove alternator, power steering pump (if equipped), and air conditioning compressor (if equipped) without disconnecting hoses, secure aside
10. Disconnect exhaust pipes at manifold flanges
11. Support transmission with floor jack and remove bellhousing-to-engine bolts
12. Attach engine hoist with load leveler to engine lifting points
13. Remove motor mount bolts and verify all connections are disconnected before lifting

Procedure

1. 1

   Remove engine from vehicle
   With engine hoist securely attached and load leveler adjusted for balance, slowly lift engine while guiding clear of transmission input shaft. Angle engine as needed using load leveler to clear firewall and core support. Once clear, lower onto engine stand and secure using 4 engine stand mounting bolts threaded into bellhousing bolt holes.
2. 2

   Remove external components
   Remove distributor (mark position before removal), spark plug wires, spark plugs, fuel pump, water pump, thermostat housing, and starter motor. Remove valve covers by unbolting 6 bolts per cover. Remove intake manifold by removing 12 intake manifold bolts in reverse of tightening sequence (work from center outward). Remove exhaust manifolds by removing 5 bolts per manifold.
3. 3

   Remove cylinder heads
   Remove rocker arms by unbolting rocker arm studs, then remove pushrods and store in order. Remove cylinder head bolts (17 per head) using proper sequence starting from outer bolts working inward. Carefully lift cylinder heads off block and set aside. Remove and discard cylinder head gaskets.
   ⚠Keep pushrods in order if reusing. Small block Chevy pushrods can wear unevenly and should be returned to original positions.
4. 4

   Remove timing cover and harmonic balancer
   Remove crankshaft pulley bolt and washer. Install harmonic balancer puller and remove balancer from crankshaft snout (do not pry or hammer). Remove timing cover bolts (8 total) and remove timing cover. Remove front crankshaft seal from timing cover.
   ⚠️Never use a jaw-type puller or strike the harmonic balancer. This will damage the crankshaft keyway or balancer.
5. 5

   Remove timing chain and gears
   Verify timing marks are aligned (crankshaft and camshaft sprocket dots should face each other). Remove camshaft sprocket bolts (3 bolts) and slide timing chain with both sprockets off crankshaft and camshaft. Note camshaft thrust button location behind camshaft gear.
6. 6

   Remove oil pan and oil pump
   Remove oil pan bolts (20 bolts total around perimeter). Lower oil pan from engine block. Remove oil pump mounting bolt and pull oil pump with pickup tube assembly downward out of engine block.
7. 7

   Remove camshaft
   Carefully slide camshaft straight out of engine block, rotating slowly to clear cam lobes past lifter bores. Use caution not to damage camshaft bearings or lobes. Support camshaft throughout removal as it is long and can bend under its own weight.
   ⚠Camshaft must be pulled straight out without tilting or levering against cam bearings. Bearing damage will require machining.
8. 8

   Install new short block components verification
   With the new short block on the engine stand, verify all internal components are properly installed. Check that main bearing caps are torqued, connecting rod caps are torqued, camshaft is installed with correct endplay, and crankshaft rotates freely by hand. Verify piston ring gaps are properly positioned (end gaps staggered at 90-degree intervals). Confirm oil gallery plugs are installed and sealed.
   ℹ️If short block supplier did not install camshaft, it must be installed now with fresh assembly lube on all lobes and bearing journals.
9. 9

   Install oil pump and oil pan
   Prime oil pump by filling with engine oil and rotating pump shaft. Insert oil pump with pickup tube into block, aligning pump driveshaft with distributor drive gear slot. Install oil pump mounting bolt. Clean oil pan and block mating surfaces thoroughly. Apply thin bead of RTV silicone to front and rear main cap corners. Install new oil pan gasket and position oil pan onto block. Install oil pan bolts and tighten in criss-cross pattern from center outward.
10. 10

    Install timing chain and gears
    Apply assembly lube to crankshaft and camshaft sprocket surfaces. Install camshaft thrust button on front of camshaft. Slide camshaft sprocket and crankshaft sprocket onto their respective shafts simultaneously with timing chain engaged. Align timing marks so crankshaft sprocket dot faces camshaft sprocket dot (dots should face each other on a centerline). Install camshaft sprocket bolts with thread locker and torque to specification.
11. 11

    Install timing cover and harmonic balancer
    Install new front crankshaft seal into timing cover using seal driver or appropriate socket. Clean timing cover and block mating surfaces. Apply thin bead of RTV silicone to timing cover gasket surfaces and position new timing cover gasket. Install timing cover and install all timing cover bolts, tightening in criss-cross pattern. Apply anti-seize to crankshaft snout and slide harmonic balancer onto crankshaft, aligning keyway. Install balancer bolt with washer and torque to specification.
12. 12

    Install cylinder heads
    Clean cylinder head and block mating surfaces thoroughly, ensuring no gasket material or debris remains. Position new cylinder head gaskets on block with UP marking facing upward and orientation tabs properly located. Carefully lower cylinder heads onto block, aligning over dowel pins. Install cylinder head bolts with thread sealant on threads that enter water jackets. Torque cylinder head bolts in proper sequence (start at center, work outward in spiral pattern) in three stages: first pass to 30 ft-lb, second pass to 60 ft-lb, final pass to 65 ft-lb.
13. 13

    Install pushrods and rocker arms
    Apply assembly lube to pushrod ends and install pushrods through cylinder head guide holes, seating in lifter cups. Install rocker arms on studs, ensuring each pushrod is properly seated in rocker arm socket. Install rocker arm balls and nuts. Adjust valves by rotating engine to position each valve at its lifter base circle (pushrod can be rotated freely by hand), then tighten rocker nut until all lash is eliminated plus one additional turn. Complete for all 16 valves.
    ℹ️Hydraulic lifters require one turn past zero lash. Over-tightening will pump lifter down and cause valvetrain noise or damage.
14. 14

    Install intake and exhaust manifolds
    Clean all manifold mating surfaces. Position new intake manifold gaskets and end seals with RTV applied to corner joints between gaskets and seals. Lower intake manifold into position and install all intake manifold bolts finger-tight. Torque intake manifold bolts in proper sequence (center to ends) to specification. Install new exhaust manifold gaskets and position exhaust manifolds. Install exhaust manifold bolts and torque to specification.
15. 15

    Install remaining external components
    Install water pump with new gasket and torque bolts to specification. Install thermostat and housing. Install fuel pump with new gasket. Install distributor, aligning rotor with mark made during disassembly. Install spark plugs torqued to specification with anti-seize on threads. Install spark plug wires in correct firing order (1-8-4-3-6-5-7-2). Install starter motor. Install valve covers with new gaskets. Install all remaining brackets, pulleys, and accessories.
16. 16

    Install engine into vehicle
    With engine secured to hoist and load leveler, carefully lower engine into engine bay at appropriate angle to clear firewall and core support. Guide engine onto transmission input shaft, ensuring pilot bearing engages properly. Align engine mounts and install motor mount bolts. Install bellhousing-to-engine bolts and torque to specification. Remove engine hoist.
    ⚠Have assistant guide transmission input shaft during engine installation to prevent clutch disc or pilot bearing damage.
17. 17

    Reconnect all systems and fill fluids
    Reconnect exhaust pipes to manifolds with new gaskets. Reinstall alternator, power steering pump, and air conditioning compressor (if equipped). Reconnect all electrical connections, vacuum lines, and fuel lines using labels for reference. Reconnect carburetor linkage. Install radiator, fan shroud, and fan assembly. Reconnect all cooling system hoses. Install new oil filter and fill engine with 5 quarts of 5W-30 conventional engine oil. Fill cooling system with 10 quarts of DEX-COOL coolant (or appropriate coolant type). Fill power steering reservoir if equipped. Reinstall air cleaner assembly.
    ⚠Double-check all fluid levels before starting engine. Low oil pressure on initial start can cause catastrophic damage to new short block.
18. 18

    Initial start and break-in procedure
    Reconnect negative battery cable. Set initial ignition timing to 4 degrees BTDC. Prime oil system by cranking engine with ignition disabled until oil pressure registers on gauge (remove coil wire). Reconnect coil wire and start engine. Immediately verify oil pressure reads at least 20 PSI at idle. Run engine at 2000 RPM for 20 minutes to break in camshaft and lifters, varying RPM slightly every few minutes. Monitor for leaks, unusual noises, or overheating. After initial break-in, allow engine to idle and recheck all connections, fluid levels, and torque on valve cover bolts and intake manifold bolts.
    ⚠️If oil pressure does not register within 10 seconds of starting, immediately shut down engine and investigate cause before continuing.
    ⚠New camshaft and lifters require elevated RPM for first 20 minutes to ensure proper break-in. Failure to do so may cause premature cam lobe wear.

Reassembly

1. Reinstall hood, aligning with marks made during removal
2. Perform final torque check on all critical fasteners after engine reaches operating temperature
3. Adjust carburetor idle mixture and speed as needed
4. Road test vehicle and monitor oil pressure, coolant temperature, and engine performance
5. After 50 miles, retorque cylinder head bolts and readjust valves as needed
6. Change engine oil and filter after 500 miles of break-in period

Verification

• Verify oil pressure reads 40-60 PSI at 2000 RPM and minimum 10 PSI at hot idle
• Confirm no oil, coolant, or fuel leaks from any gaskets or seals
• Verify engine idles smoothly without unusual noises, vibrations, or misfires
• Confirm coolant temperature remains in normal range (160-195°F) during operation
• Check that all electrical systems, gauges, and accessories function properly
• Verify exhaust system has no leaks at manifold connections
• Confirm valve adjustment is correct by checking for excessive valvetrain noise

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