Intake Manifold

Removal and replacement of the intake manifold on a 1972 Ford F-100 with 302ci V8 engine, including carburetor removal, distributor marking, and cooling system service.

Warnings

Tools required

Parts

• Intake manifold gasket set × 1 — Fel-Pro MS90032 or equivalent
• Intake manifold end seals (front and rear) × 1 — Included in gasket set or separate
• Carburetor base gasket × 1 — Use OEM specification
• Thermostat housing gasket × 1 — Use OEM specification
• RTV silicone sealant (high-temp) × 1 — Permatex Ultra Black or equivalent
• Thread sealer (non-hardening) × 1 — Permatex #2 or equivalent

Fluids

• Ethylene glycol green 50/50 coolant — 15 qt

Preparation

1. Ensure engine is completely cold to the touch
2. Park vehicle on level ground and set parking brake
3. Disconnect negative battery cable
4. Place drain pan under radiator and drain coolant by opening petcock at bottom of radiator
5. Remove air cleaner assembly and set aside
6. Take photos of vacuum line routing and carburetor linkage connections for reference during reassembly

Procedure

1. 1

   Disconnect fuel and vacuum lines
   Disconnect fuel line at carburetor inlet using two wrenches to prevent twisting the fuel line. Plug fuel line with rubber cap or bolt to prevent spillage. Disconnect and label all vacuum lines from carburetor, intake manifold, and distributor vacuum advance. Use vacuum caps or golf tees to plug open ports.
2. 2

   Remove carburetor
   Disconnect throttle linkage, kickdown linkage (if automatic transmission), and choke cable from carburetor. Disconnect PCV hose from carburetor base. Remove the 4 carburetor mounting nuts using appropriate socket. Carefully lift carburetor straight up off studs and set aside on clean surface. Stuff clean shop towels into intake manifold openings to prevent debris entry.
3. 3

   Mark and remove distributor
   Using white paint pen, mark the position of distributor rotor relative to distributor body. Mark distributor body position relative to intake manifold for installation reference. Remove distributor hold-down bolt and clamp. Pull distributor straight up and out of engine. Note the rotor will rotate slightly as gear disengages - this is normal.
4. 4

   Disconnect cooling system components
   Remove upper radiator hose from thermostat housing on intake manifold front. Disconnect heater hoses from intake manifold fittings (one on each side of manifold). Disconnect temperature sending unit wire. If equipped with coolant temperature gauge, disconnect gauge line from manifold fitting.
5. 5

   Disconnect remaining components
   Disconnect coil wire from distributor cap (if not already removed). Remove spark plug wire looms or brackets mounted to intake manifold. Disconnect any remaining vacuum lines, emissions components, or accessories mounted to intake manifold. Remove alternator bracket or air conditioning compressor bracket if it bolts to intake manifold.
6. 6

   Remove intake manifold bolts
   Remove the intake manifold mounting bolts working from the outer ends toward the center (reverse of the tightening sequence) to prevent warping. Bolts are located along outer edges of manifold in valley between cylinder heads. Note that bolt lengths may vary - mark or organize them by position for correct reinstallation.
7. 7

   Remove intake manifold
   Carefully break manifold loose from cylinder heads by gently prying at cast bosses or ears - never pry against machined sealing surfaces. Lift manifold straight up and away from engine. Expect coolant to drain from passages. Remove and discard old gaskets and end seals. Remove shop towels from manifold openings.
8. 8

   Clean all mating surfaces
   Using plastic gasket scraper, thoroughly remove all old gasket material from cylinder head surfaces and intake manifold bottom. Take extreme care not to gouge aluminum surfaces. Clean surfaces with brake cleaner and shop towels. Use wire brush to clean manifold bolt holes in cylinder heads. Blow out holes with compressed air if available. Inspect cylinder head surfaces with straight edge for warpage - surface should be flat within 0.003 inches.
9. 9

   Prepare and position new gaskets
   Apply thin bead of RTV silicone at the 4 corners where intake manifold end seals meet cylinder head gaskets (front and rear block rails). Position front and rear intake manifold end seals on block rails with chamfered edge toward cylinder heads. Place intake manifold gaskets on cylinder heads, ensuring port openings align correctly and all bolt holes line up. Some gaskets have alignment tabs or printing indicating 'front'.
10. 10

    Install intake manifold
    Apply thread sealer to threads of all 12 intake manifold bolts. Carefully lower intake manifold into position, ensuring gaskets remain in place and all bolt holes align. Start all 12 bolts by hand before tightening any. 18.0 lb-ft (25.0 Nm) Proper sequence is critical to prevent gasket leaks and warpage. Verified detail (Factory torque for the 1972 Ford 302 (Windsor) intake manifold bolts is approximately 18.0 lb-ft (25.0 Nm), which is plausible, but must be verified against Ford shop manual. The 23-25 range is roughly correct for this application, though some references cite up to 32 ft-lb for the final pass; flagging for direct verification.): 18.0 lb-ft (25.0 Nm)
11. 11

    Reinstall distributor
    Rotate crankshaft until number 1 cylinder is at top dead center on compression stroke (both valves closed, timing mark aligned). Position distributor rotor to align with marks made during removal. Insert distributor into engine, engaging oil pump drive shaft. Distributor should drop fully into place with hold-down clamp flush against manifold. Install hold-down clamp and bolt finger-tight only - timing will need to be set after startup.
12. 12

    Reconnect cooling system components
    Install new thermostat housing gasket if removed. Reconnect upper radiator hose to thermostat housing. Reconnect both heater hoses to intake manifold fittings. Reconnect temperature sending unit wire and gauge line if equipped. Ensure all hose clamps are tight.
13. 13

    Reinstall carburetor and connections
    Remove shop towels from manifold openings. Install new carburetor base gasket. Set carburetor onto studs, ensuring gasket is properly positioned. Install and tighten 4 mounting nuts in crisscross pattern to 12-15 ft-lb. Reconnect PCV hose, throttle linkage, kickdown linkage, and choke cable. Reconnect fuel line to carburetor using two wrenches.
14. 14

    Reconnect vacuum lines and accessories
    Reconnect all vacuum lines according to photos taken during disassembly or vacuum hose routing diagram. Ensure each connection is secure and hoses are not kinked. Reinstall any brackets, wire looms, or accessories removed from manifold. Reconnect coil wire if removed.
15. 15

    Refill cooling system
    Close radiator petcock. Fill cooling system with approximately 12-14 quarts of 50/50 ethylene glycol green coolant mixture through radiator cap opening until radiator is full. Start engine and allow to warm up to operating temperature with radiator cap off. Add coolant as needed to maintain level. Squeeze upper radiator hose to burp air from system. Once thermostat opens and coolant circulates, top off radiator and install cap. Check for leaks around intake manifold, hoses, and fittings. Verified detail (A 302 V8 cooling system capacity is roughly 14-15 quarts total INCLUDING heater and block, but only a portion was drained via the radiator petcock. Stating a flat 15-quart refill through the radiator cap is misleading since the block was not fully drained. Coolant type (ethylene glycol green) is era-appropriate and correct.): Fill cooling system with a 50/50 ethylene glycol green coolant mixture through the radiator cap opening; add only the amount that was drained (typically 6-8 quarts if only the radiator was drained). Total system capacity is approximately 14-15 quarts.

Reassembly

1. Reinstall air cleaner assembly
2. Reconnect negative battery cable
3. Double-check all hose connections, vacuum lines, and linkages are secure
4. Verify no tools or shop towels were left in engine compartment

Verification

• Start engine and check for coolant, fuel, or vacuum leaks around intake manifold gaskets
• Allow engine to reach operating temperature and verify cooling system is functioning properly without overheating
• Check for smooth idle - rough idle may indicate vacuum leak or incorrect distributor timing
• Set ignition timing to factory specification (typically 6-10 degrees BTDC at idle with vacuum advance disconnected)
• Tighten distributor hold-down bolt after timing is set
• Recheck coolant level after engine cools and top off if necessary
• Test drive vehicle to verify proper engine performance and no overheating under load

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