Should I add these when I put my oem exhaust manifolds?

[Plyrr471]

So I’m referbing my exhaust manifolds and wonder if I should add these plug insulator shields? I believe one gets attached via a manifold bolt but the other via head bolts. Regarding the one that requires head bolts, I assume it would be foolish of me to remove and retorque the two head bolts securing the double shield on my already built engine that has about 30k on it.
Is adding these even worth the effort?
Thanks guys

 

[pnora]

You can install them and re-torque the two bolts with no issues. May not be a bad idea to re-torque all the bolts.

 

[Jerry Hall]

By all means, protect your sparkplug wires. I agree with @pnora

 

[SgtSuperbird]

I've had them on all my cars that are supposed to have them.