Long Block Replacement

Complete removal and replacement of the 8.0L V10 long block assembly, including disconnection of all engine ancillaries, removal from vehicle, and installation of replacement long block with all external components transferred.

Warnings

Tools required

Parts

• Long block assembly (8.0L V10) × 1 — Use OEM specification or verified remanufactured unit
• Exhaust manifold gasket set × 1 — Use OEM specification
• Intake manifold gasket set × 1 — Use OEM specification
• Valve cover gaskets × 2 — Use OEM specification
• Oil filter × 1 — Use OEM specification
• Oil drain plug crush washer × 1 — Use OEM specification
• Coolant hoses (if deteriorated) × 1 — Inspect and replace as needed
• Serpentine belt × 1 — Use OEM specification
• Engine oil × 11 — 10W-30 conventional
• Engine coolant concentrate × 12 — Ethylene glycol
• Anti-seize compound × 1 — High temperature rated
• RTV gasket maker (if required) × 1 — Use OEM specification
• Thread locker (medium strength) × 1 — Blue Loctite or equivalent

Fluids

• engine_oil — 11 qt
• coolant — 24 qt

Preparation

1. Park vehicle on level, solid ground with adequate overhead clearance for engine hoist operation (minimum 8 feet recommended).
2. Disconnect negative battery cable, then positive battery cable. Remove battery from vehicle to provide additional working clearance.
3. Drain engine coolant completely by opening radiator petcock and removing lower radiator hose. Capture coolant in appropriate container.
4. Drain engine oil by removing oil drain plug. Allow adequate time for complete drainage due to large oil capacity.
5. Relieve fuel system pressure by removing fuel pump relay and cranking engine until it stalls, then crank for additional 5 seconds.
6. Raise front of vehicle and support on jack stands at manufacturer-specified lift points for underside access.
7. Remove engine cover panels and any plastic shields in engine bay.
8. Take comprehensive photos of all engine bay connections, routing of hoses, wiring harness positions, and belt routing for reassembly reference.

Procedure

1. 1

   Remove Hood Assembly
   Mark hood hinge positions with paint pen or marker for reinstallation alignment. With assistant support, remove hood mounting bolts from both hinges. Carefully lift hood away from vehicle and store in protected area where it will not be damaged.
2. 2

   Disconnect Air Intake System
   Loosen clamps on air intake tube at throttle body and air filter housing. Disconnect any air intake temperature sensor electrical connector if equipped. Remove air intake tube assembly. Remove air filter housing mounting bolts and lift housing from engine bay. Disconnect any vacuum lines connected to intake system.
3. 3

   Remove Radiator and Cooling System Components
   Disconnect upper and lower radiator hoses from engine. Disconnect transmission cooler lines from radiator (cap open lines to prevent contamination). Remove radiator fan shroud mounting bolts and lift fan shroud from radiator. Disconnect overflow tank hose. Remove radiator mounting bolts and carefully lift radiator from vehicle. Remove cooling fans if still attached to radiator shroud. Disconnect heater hoses from engine at firewall connections.
4. 4

   Disconnect Fuel System
   Using appropriate fuel line disconnect tools, separate fuel supply and return lines at engine connections. Have shop towels ready to catch residual fuel. Cap open fuel lines immediately to prevent contamination and fuel spillage.
5. 5

   Remove Serpentine Belt and Accessory Drive Components
   Release belt tensioner and remove serpentine belt. Remove power steering pump mounting bolts and position pump aside with hoses still connected (secure with wire to prevent hose strain). Remove alternator mounting bolts and disconnect alternator wiring, then remove alternator. Remove AC compressor mounting bolts and position compressor aside with refrigerant lines still connected (secure with wire; do not disconnect refrigerant lines). Remove belt tensioner assembly mounting bolts and remove tensioner.
6. 6

   Disconnect Electrical Connections
   Disconnect all engine electrical connectors including: coolant temperature sensors, coolant temperature sensors, oil pressure sender, camshaft position sensors, crankshaft position sensor, throttle position sensor, idle air control valve, injector harness connectors (both banks), ignition coil connectors, and any additional engine management sensors. Disconnect main engine harness connectors at firewall or fender-mounted junction points. Secure all disconnected harnesses away from engine removal path.
7. 7

   Remove Throttle Body and Intake Plenum
   Disconnect throttle cable (and cruise control cable if equipped) from throttle body linkage. Remove throttle cable bracket mounting bolts. Disconnect all vacuum lines from intake plenum, labeling each for reinstallation. Remove throttle body mounting bolts and separate throttle body from intake plenum. Remove intake plenum mounting bolts working from outer bolts toward center. Carefully lift intake plenum from engine, noting gasket condition and position.
8. 8

   Remove Exhaust System Connection
   Working from underneath vehicle, spray exhaust manifold flange bolts with penetrating oil and allow to soak. Remove exhaust pipe flange bolts/nuts connecting exhaust pipes to both exhaust manifolds. Support exhaust system weight with jack or wire to prevent damage to hangers. Separate exhaust pipes from manifolds and lower exhaust system enough to clear engine during removal.
9. 9

   Remove Valve Covers
   Disconnect any remaining components attached to valve covers (PCV hoses, breather hoses, ignition coil brackets). Remove valve cover mounting bolts in reverse of tightening sequence (work from ends toward center). Carefully pry valve covers loose if sealed with gasket maker, being careful not to damage mating surfaces. Lift valve covers from cylinder heads.
   Torque spec

   Cover Bolts16 Nm (12 lb-ft)
10. 10

    Separate Transmission from Engine
    Support transmission with transmission jack placed under transmission pan (use wood block to distribute load). Remove transmission bellhousing-to-engine mounting bolts, noting different bolt lengths and positions. For manual transmission, remove clutch hydraulic line at transmission. Carefully slide transmission straight back approximately 2 inches to disengage input shaft from clutch disc/pressure plate. Lower transmission jack slightly and roll transmission away from work area. Inspect clutch assembly condition while exposed.
11. 11

    Disconnect Remaining Engine Mounts and Connections
    Remove engine mount through-bolts from both driver and passenger side motor mounts. Check for any remaining connections that may restrict engine removal: ground straps, additional wiring harnesses, vacuum lines, coolant lines, or brackets. Remove starter motor mounting bolts and lower starter from bellhousing, disconnect starter wiring, and remove starter from vehicle.
12. 12

    Position Engine Hoist and Attach Lifting Equipment
    Position engine hoist at front of vehicle with adequate clearance for engine removal path. Attach heavy-duty lifting chains or straps to factory engine lift points (typically located at cylinder head bolt locations or manifold mounting points). Thread lift bolts into engine if using bolt-in lifting brackets. Attach chains/straps to engine leveler bar on hoist. Take up slack in hoist until chains/straps are just taut but engine weight is still supported by mounts. Verify all attachments are secure and properly rated for engine weight.
13. 13

    Remove Engine from Vehicle
    Slowly lift engine with hoist while monitoring all clearances around engine bay. Use engine leveler to adjust engine angle as needed to clear firewall, frame rails, and front crossmember. The engine will need to be tilted with transmission end higher than front to clear the Viper's low hood line. Have assistant guide engine and watch for any hung connections or contact points. Once engine is clear of motor mounts, continue lifting while simultaneously pulling hoist away from vehicle. Lift engine completely clear of engine bay and move to suitable work area. Lower engine onto engine stand or heavy-duty workbench.
14. 14

    Transfer External Components to New Long Block
    Remove and transfer all external components from old engine to new long block in systematic order: exhaust manifolds (apply anti-seize to studs during installation), intake manifold and related components, water pump and thermostat housing, oil filter adapter, oil pressure sender, temperature sensors, camshaft and crankshaft position sensors, throttle body mounting flange, accessory brackets, motor mount brackets, bellhousing dust cover, flywheel/flexplate (inspect for cracks or hot spots; replace if questionable), clutch assembly (if manual transmission; inspect and replace if worn), and any remaining sensors or fittings. Install all new gaskets during component transfer. Torque all fasteners to factory-specified values (verify flywheel, exhaust manifold, and intake manifold torque specs in the service manual; apply thread locker to flywheel bolts as specified).
    Torque spec

    Exhaust Manifold Nuts30 Nm (22 lb-ft)

    Intake Manifold Bolts25 Nm (18 lb-ft)

    Flywheel Bolts95 Nm (70 lb-ft)

    Gasket Bolts20 Nm (15 lb-ft)

    Sensor Bolts11 Nm (8 lb-ft)

    Mounting Bolts27 Nm (20 lb-ft)
15. 15

    Install New Long Block into Vehicle
    Attach lifting equipment to new long block at same lift points used for removal. Lift engine to appropriate height and position hoist at front of vehicle. Carefully guide engine into engine bay, using engine leveler to maintain proper angle for clearance. The procedure is reverse of removal: engine must enter at angle with front lower than rear. Have assistant guide engine and monitor clearances on both sides. Once engine is positioned over motor mounts, use leveler to align engine with mount locations. Lower engine slowly onto motor mounts, making fine adjustments to align mount bolt holes. Install motor mount through-bolts and tighten to secure engine in chassis.
16. 16

    Reconnect Transmission to Engine
    Apply small amount of high-temperature grease to transmission input shaft splines. For manual transmission, verify clutch disc is properly centered using alignment tool if clutch was replaced. Position transmission on transmission jack and raise into position behind engine. Align transmission input shaft with clutch disc/pilot bearing (manual) or torque converter (automatic). Carefully slide transmission forward, ensuring input shaft engages properly without binding. Once transmission bellhousing contacts engine block, install all bellhousing-to-engine mounting bolts in their correct positions and tighten to specification. Reconnect clutch hydraulic line if equipped with manual transmission.
    Torque spec

    Transmission-to-Engine Bolts68 Nm (50 lb-ft)
17. 17

    Install Valve Covers
    Clean valve cover mating surfaces on cylinder heads thoroughly, removing any old gasket material or sealant. Install new valve cover gaskets in valve cover grooves (use small dabs of RTV in corners if gasket design requires). Position valve covers on cylinder heads, ensuring gaskets remain properly seated. Install valve cover bolts and tighten in sequence from center outward to specified torque. Do not overtighten as this can distort covers and cause leaks. Reconnect PCV system and breather hoses.
    Torque spec

    Cover Bolts16 Nm (12 lb-ft)
18. 18

    Reconnect Exhaust System
    Raise exhaust system into position and align exhaust pipe flanges with exhaust manifold flanges. Install new exhaust manifold gaskets if not already installed. Install exhaust flange bolts/nuts and tighten evenly to prevent warping flanges. Final tighten to specification once all fasteners are started. Remove any temporary exhaust system supports.
19. 19

    Install Intake Plenum and Throttle Body
    Install new intake plenum gaskets on intake manifold mating surfaces. Position intake plenum carefully to avoid disturbing gaskets. Install plenum mounting bolts and tighten in sequence from center outward to specification. Install throttle body with new gasket on intake plenum and tighten mounting bolts evenly. Install throttle cable bracket and connect throttle cables, adjusting for proper free play. Reconnect all vacuum lines to intake plenum according to labels or reference photos taken during disassembly.
    Torque spec

    Intake Manifold Bolts25 Nm (18 lb-ft)
20. 20

    Reconnect All Electrical Connections
    Reconnect all engine electrical connectors in reverse order of removal, referring to labels and photos taken during disassembly. Ensure all connectors are fully seated and locking tabs are engaged. Reconnect main engine harness connectors at firewall or fender junction points. Reconnect starter motor wiring. Route all wiring harnesses in original paths, using existing clips and securing points to prevent chafing or heat damage. Reconnect all engine management sensors, ensuring connectors are clean and fully seated.
21. 21

    Install Accessory Drive Components and Belt
    Install belt tensioner assembly and tighten mounting bolts. Position AC compressor in mounting location and install mounting bolts, tightening to specification. Position power steering pump in mounting location and install mounting bolts, tightening to specification. Install alternator and connect alternator wiring, tightening mounting bolts to specification. Route new serpentine belt according to belt routing diagram (reference photo taken during disassembly). Use tensioner tool to release tensioner and slip belt onto tensioner pulley last. Verify belt is properly seated in all pulley grooves.
22. 22

    Reconnect Fuel System and Cooling System
    Reconnect fuel supply and return lines at engine connections, ensuring fuel line quick-disconnects are fully seated and locked. Install radiator into mounting location and install radiator mounting bolts. Connect transmission cooler lines to radiator. Install fan shroud and cooling fans, tightening all mounting bolts. Connect upper and lower radiator hoses to engine, positioning clamps properly for secure seal without over-tightening. Reconnect heater hoses at firewall connections. Connect overflow tank hose to radiator.
23. 23

    Reinstall Air Intake System
    Install air filter housing in engine bay and secure with mounting bolts. Install air intake tube, connecting to throttle body and air filter housing. Tighten clamps securely. Reconnect any air intake temperature sensor electrical connector if equipped. Reconnect any vacuum lines to intake system. Install new air filter element.
24. 24

    Fill Fluids and Perform Initial Checks
    Install new oil drain plug crush washer and install drain plug, torquing to specification. Install new oil filter, lubricating filter gasket with clean oil before installation. Fill engine with approximately 8 quarts of oil per factory specification (verify grade and final level on dipstick after filling). Fill cooling system with 50/50 mixture of ethylene glycol coolant and distilled water to proper level in radiator and overflow tank (verify total system capacity against factory service manual). Leave radiator cap off initially to allow air bleeding. Reinstall battery and connect positive cable, then negative cable. Verify all tools and loose items are removed from engine bay.
    Torque spec

    Oil Drain Plug35 Nm (26 lb-ft)
25. 25

    Initial Start and Break-In
    Before starting, turn ignition key to ON position without starting to prime fuel system; repeat 3-4 times. Prime oil system by cranking engine in short bursts (10-15 seconds each with rest intervals to avoid starter overheating) with fuel pump relay removed or ignition coils disabled, allowing oil pressure to build. Reinstall fuel pump relay or reconnect ignition coils. Start engine and immediately verify oil pressure indication on gauge. Monitor for any fluid leaks, unusual noises, or warning lights. Allow engine to idle until cooling system thermostat opens and coolant begins circulating (verify by feeling upper radiator hose becoming hot). Check coolant level and add as necessary to maintain proper level as air is purged from system. Install radiator cap once coolant level is stable. Check for any exhaust leaks at manifold flanges. Verify all gauges reading normally. Allow engine to reach full operating temperature while monitoring closely.
26. 26

    Reinstall Hood and Final Inspection
    With assistant support, position hood over engine bay aligning with marks made during removal. Install hood hinge bolts and tighten securely while maintaining alignment. Make fine adjustments to hood alignment if necessary to achieve proper fit and gap consistency. Lower vehicle from jack stands. Install any remaining engine covers or plastic shields removed during disassembly. Perform final walk-around inspection of all connections, fasteners, and components. Test all electrical systems related to engine: lights, gauges, sensors. Check all fluid levels again after engine has cooled slightly.

Reassembly

1. Follow installation steps in reverse order of removal, using all new gaskets and seals.
2. Torque all fasteners to specification using proper sequence where applicable (cylinder head bolts, main bearing caps, intake manifold, exhaust manifolds).
3. Apply anti-seize compound to exhaust manifold studs and spark plug threads to prevent future seizure.
4. Use thread locker on appropriate fasteners as specified in service manual.
5. Verify all electrical connectors are fully seated with locking tabs engaged.
6. Route all wiring harnesses, vacuum lines, and fuel lines in original paths using factory clips and securing points.
7. Double-check that no tools, rags, or hardware have been left in engine bay before starting engine.

Verification

• Start engine and verify immediate oil pressure indication within 2-3 seconds.
• Allow engine to reach full operating temperature and verify cooling fan operation.
• Check for any fluid leaks at all connection points: oil pan, valve covers, intake manifold, coolant hoses, fuel lines.
• Verify no exhaust leaks at manifold connections or gasket surfaces.
• Test drive vehicle after initial warm-up, monitoring engine temperature, oil pressure, and listening for any unusual noises.
• Verify all engine-related warning lights are off and all gauges read within normal ranges.
• Recheck all fluid levels after test drive and top off as necessary.
• Check valve cover and oil pan areas for leaks after test drive.
• Perform final torque check on critical fasteners (motor mount bolts, transmission-to-engine bolts) after engine has completed heat cycle.
• Follow new engine or rebuilt engine break-in procedures as specified by engine builder or manufacturer, typically involving varied RPM operation and avoiding sustained high load for first 500-1000 miles.

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