The venerable Chevy 350 engine has been a mainstay of the industry, and is a favorite of hot-rodders and backyard mechanics. The torque specifications are required to ensure that the engine components are properly tightened. If the proper torque is not applied the motor may leak fluids or become unreliable. An over-tightened bolt can damage the threads, or break the bolt–causing time-consuming and sometimes costly repair. If the bolt is not tight enough, it may eventually back out of the threads, resulting in severe engine damage.
Lower Engine Components
The piston caps have two bolts per piston that require specific torque. You will also need to torque the main-bearing caps that keep the crankshaft in place. If you over-tighten the bolts you eliminate the small space between the bearing and journal that allows proper oiling. If you under-tighten the piston or main-cap bolts, there will be too much space, and the volume of the oil will not create the lubricated cushion around the journal.