You MUST consult a service manual for your specific 1977 Chevy 400 small block engine and intake manifold. The manual will have the proper torque sequence and specifications. Using the wrong torque can damage the intake manifold, cylinder head, or both.
General advice:
* Don't guess. Using an incorrect torque value can lead to leaks and engine damage.
* Look for markings on the intake manifold itself. Sometimes, the manufacturer stamps the torque specification onto the part.
* Use a torque wrench. This is absolutely essential to avoid over-tightening.
Several sources for service manuals include:
* Chevrolet service manuals: These are the best source, but can be expensive.
* Online repair manuals: Websites like Chilton or Haynes offer manuals, but their accuracy varies. Check reviews before purchase.
* Local auto parts store: Many auto parts stores have access to online service manual databases.
Failing to find the proper torque spec will almost certainly result in engine problems. Take the time to find the correct information before proceeding.
