A general range often quoted is between 65 and 75 ft-lbs, but this is only a rough estimate and should never be used without verifying it with the correct manual. Using an incorrect torque specification can lead to serious engine damage.
To find the correct torque specs:
1. Find your engine's specific service manual: These manuals are available from several sources, including online retailers (like eBay or Amazon), auto parts stores, or online digital archives. Make sure it's for a 1989 350 Chevy small block. The year is crucial as specs can vary slightly.
2. Look for the torque sequence: The sequence in which you tighten the main caps is just as important as the torque value itself. The manual will detail this sequence to ensure even clamping force.
3. Use a torque wrench: This is absolutely essential. Don't guess. A properly calibrated torque wrench is your only guarantee of correct tightening.
Using the wrong torque can cause problems ranging from oil leaks to catastrophic crankshaft failure. Don't risk it. Always consult the factory service manual.
