When I start my engine up I get a rubbing or scuffing noise which can be heard inside with the windows up. Under the hood it can be heard around the valve covers but this does not sound like rockers to me since it is NOT a ticking or knocking sound.

This sound is not very loud at all and can not be heard when the engine revs above idle. The noise goes away in about 5 minutes once things warm up.

I have forged .030" Mahle pistons which some say may create piston slap.
Does this sound like piston slap to you guys?

 

I also have some piston slap with SRP forged pistons. Just don't beat on it right away you should be ok as long as it doesnt get louder. Many vehicles have piston slap, even new ones.

 

So your makes this exact same scuffing sound I am describing?

 

Possibly timing chain rubbing on the front cover, which goes away as the cover heats up? (aluminum expands quicker than steel with temp)

Or maybe rubbing between cam retainer plate and cam timing sprocket? (Think mine does this a bit, results in a rubbing noise was getting better with time)