How much louder is a metal cam sprocket vs a nylong sprocket?

[collector]

I'm changing my timing chain and have an NOS timing sprocket in aluminium and nylon and also have an NOS timing sprocket in cast. My cast sprocket uses a cam thrust bearing, which is from a 4.9 and the sprocket has a lip that holds the cam bearing in place, that the 4.1 does not. I want to keep it quiet like original but want the thrust bearing to keep the cam from moving back and forth in the bore. How much louder will it be?

[bcroe]

I have changed a lot of chain sets to steel, but not on that engine. 
I could never hear any chain noise. 

I believe that nylon was used for 2 reasons.  One to save cost and
two to make sure you would eventually need to buy another car. 
Bruce Roe

[The Tassie Devil(le)]

I am in agreeance with Bruce.

Bruce.

[V63]

I have switched before and could never hear a difference?

[TJ Hopland]

I too have never heard a difference but I don't think I have ever done one with an electric fan before.  If this is in a car with an electric fan maybe you could hear something if you knew what you were listening for?  But with belt drive fans the fan noise always is louder than any chain and sprocket noise?