Ford 335 / Cleveland Torque Specs
On This Page:
Intro | Torque Specs | Notes | Mistakes | Bottom Line | Links
Intro
The 335 family is where “small-block Ford” stops being useful information.
A 351 Cleveland, Boss 351, 351M, and 400 belong to the same broad family, but Ford didn’t give them one universal pile of hardware. The Boss brings higher head and rod values, the M-block engines bring a taller-deck layout, and even the intake manifold asks whether the bolt in your hand is 5/16 or 3/8 inch before it agrees to a number.
That’s why identification comes before tightening. A Cleveland isn’t a Windsor, and a 351M or 400 isn’t just a 351C with extra iron underneath it. Get the engine wrong and that torque wrench will faithfully apply the wrong answer.
General Torque Specs
| Bottom End | Top End | ||
|---|---|---|---|
| Main Cap Bolts | 95-105 lb-ft | Head Bolts | 95-105 lb-ft1 125 lb-ft2 |
| Connecting Rod Bolts | 40-45 lb-ft1 45-50 lb-ft2 |
Rocker Arms | 17-23 lb-ft |
| Oil Pump Bolt | 23-28 lb-ft | ||
| Intake and Exhaust | Driveline Side | ||
| Intake Manifold Bolts | 19-25 lb-ft3 22-32 lb-ft4 |
Flywheel / Flexplate Bolts | 75-85 lb-ft |
| Exhaust Manifold Bolts | 18-24 lb-ft | Pressure Plate Bolts | 35 lb-ft |
| Starter Bolts | 25-35 lb-ft | ||
| External Engine | |||
| Harmonic Damper Bolt | 70-90 lb-ft | Water Pump Bolts | 15-20 lb-ft |
| Crank Pulley Bolts | 35-50 lb-ft | Fuel Pump Bolt / Nut | 10-15 lb-ft 14-20 lb-ft |
| Camshaft Sprocket Bolt | 40-45 lb-ft | Valve Cover Bolts | 5-10 lb-ft |
| Camshaft Thrust Plate Bolts | 9-12 lb-ft | Oil Pan Bolts | 10-15 lb-ft |
| Timing Cover Bolts | 12-15 lb-ft | Distributor Hold-Down Bolt | 20 lb-ft |
1 Standard 351C, 351M, and 400 335-series hardware.
2 Boss 351 hardware.
3 5/16 in. intake manifold bolts.
4 3/8 in. intake manifold bolts.
That Boss 351 split isn’t decorative trivia. Standard 335-series head bolts sit at 95-105 lb-ft and rod bolts at 40-45 lb-ft, while Boss hardware moves to 125 lb-ft at the heads and 45-50 lb-ft at the rods. “It is still a 351 Cleveland” isn’t a torque procedure.
The intake manifold tells a different story. Its specification follows bolt size rather than engine badge: 19-25 lb-ft for 5/16-inch bolts and 22-32 lb-ft for 3/8-inch bolts. Measure or identify the fastener. Displacement can’t answer a question it was never given.
Aftermarket bolts, studs, rods, rocker gear, or aluminum heads can bring their own torque and lubrication instructions. Once one replaces the factory piece, the old chart doesn’t get a vote out of nostalgia; the specification supplied with the replacement part outranks the general factory-style number.
Important Notes
- The 335-series label puts Cleveland and M-block engines under one roof; it doesn’t make them roommates who can swap everything in the closet. Deck height, bellhousing arrangement, and surrounding hardware still have to match the engine being assembled.
- Boss 351 hardware gets its own head and rod figures. The performance version looks enough like an ordinary 351C to tempt a shortcut and differs enough to make you regret it.
- In this chart, bolt diameter calls the shots on intake-manifold torque. A 5/16-inch fastener and a 3/8-inch fastener may sit on the same manifold without wanting the same clamping load.
- The table runs from 9-12 lb-ft camshaft thrust-plate bolts clear up to 125 lb-ft Boss head bolts. Same family, yes. Same treatment, not even close.
- Valve covers and oil pans remain light sealing pieces. If 5-10 or 10-15 lb-ft won’t stop the leak, inspect the flange and gasket before adding more leverage.
Common Mistakes
- Using Windsor specifications because both engines were reduced to “small-block Ford.” That description belongs in conversation, not on your torque wrench.
- Putting standard 351C head and rod figures on Boss 351 hardware just because the displacement number looked familiar.
- Treating a 351M or 400 as though the taller M-block layout changed nothing except deck height. Family resemblance doesn’t make every component or installation detail identical.
- Applying the 3/8-inch intake value to a 5/16-inch bolt because both fasteners happen to hold the same manifold. The smaller bolt doesn’t care about that argument.
- Trying to solve a valve-cover or oil-pan leak with more torque after the sealing surface has already started bending. More clamping sure isn’t the same as better sealing.
Bottom Line
The 335 family shows why knowing the valve covers isn’t enough to know the engine.
Cleveland, Boss, 351M, and 400 hardware share enough ancestry to look familiar and enough differences to punish lazy identification. Sometimes the engine version calls the number. Sometimes it’s the bolt diameter.
Identify both before tightening. A torque wrench can repeat a mistake just as accurately as it repeats the right answer.
