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BoxWrench Instructional Engine Building, Carburetor Tuning, Transmission swapping and Harley Davidson Maintenance & Repair DVD samples on YouTube

Generation Two Oldsmobile V8

260, 307, 330, 350, 400, 403, 425, 455 Cid

Firing Order

Cylinder Numbering Distributor Rotation

Rotor Under Cap Spins:



Torque Specs

These specs may not be correct for your application.

Verify your engine specs with a service manual for your year and model.

always torque bolts in three equal increments
Bolts or Parts Lube or Sealer Torque to:
Main Caps (2 bolt) Engine Oil ft-lbs.
Inner Main Caps (4 bolt) Engine Oil ft-lbs.
Outer Main Caps (4 bolt) Engine Oil ft-lbs.
Outer Main Caps (4 bolt) Engine Oil ft-lbs.

If you are using ARP bolts, you MUST use
their specs.  Click Here!
Connecting Rod Bolt Engine Oil ft-lbs.
Connecting Rod Bolt Engine Oil ft-lbs.

Cylinder Heads

Engine oil

(blind hole)


(water jacket)


Rocker Studs (screw-in) Engine Oil ft-lbs.
Oil Pump Engine Oil ft-lbs.
Oil Pan Engine Oil ft-lbs.
Cam Sprocket (upper gear) Thread Locker ft-lbs.
Timing Cover Engine Oil ft-lbs.

Intake Manifold

(Cast Iron Heads)

Non- Hardening Sealer ft-lbs.
Valve Cover Engine Oil ft-lbs.
Exhaust Manifold Anti-Seize Lubricant ft-lbs.
Spark Plugs No Lube or Sealer ft-lbs.

Flexplate (Automatic)

Flywheel (Clutch)

Thread Locker ft-lbs.
Clutch Pressure Plate Thread Locker ft-lbs.


(Harmonic Damper)

Engine Oil ft-lbs.


(Transmission to Block)

Engine Oil ft-lbs.

Head Bolt Tightening Sequence

     New Items Available

New Harley Davidson
Maintenance & Repair

New Book/DVD Combo
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160 Pages and 2hrs of Video

Holley Carburetor
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Basic Engine
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Over 3hrs of Video