manifold hardware
 

is it necessary to replace all copper lock nuts on intake and exhaust manifolds on reassembly? should the studs be replaced also?

Your car did not have copper plated nuts originally , maybe lock nuts on the intake if '69 or newer , but not copper plated . The exhaust is standard hardware .

These parts only need to be replaced if damaged in some way. Replacing studs is pretty labor intensive, and risks damaging the threads in the aluminum. Aesthetics are a different story. The copper plated nuts with a radial slit are nice to have because the slit distorts the thread and creates a lock effect, but properly torqued regular nuts (or the normal but sometimes problematic barrel nuts) do the job fine.

A turbo manifold is subject to high heat which is generated from the turbo charger, this heat along with vibration from a high revving engine is a environment where nuts expand from the heat and work there way loose. This is the main reason why a lock nut should be used when installing a turbo or manifold.
Your turbo flange lock nuts will be subject to higher temperatures than your manifold to cylinder head ones, we recommend replacing your lock nuts every time they are taken off. MyCCPay Log In