I have a 383sbc the engine has keithblack .040 over hyperutectic pistons,dart ironeagle heads with 72cc chambers,comp280 magnum flat tappet cam,demon 650 carb, rpm airgap intake.when the engine is cold it makes a noise that sounds like rattling. when temp reaches 180 the noise gets a little quieter but is still there. Is this normall? The engine runs strong.  

valvetrain noise...

???  

Could be piston slap.

First thing you should do, with the engine cold, pull the valve covers and make sure none of the rockers are loose.

If everything's good up top, I'd suspect you've got a case of piston slap. That's whent he pistons are cold and leave a little extra gap between the rings and cylinder walls. Once the engine warms up, the noise gets better or goes away entirely. Cast pistons seem to be more susceptible to this than forged pistons.  

Thanks for the reply. There is a long story behind this 383.I will say the engine came from speed-o-motive.  It has been re-ringed once by speed-o-motive & they also ran it on the dyno to break it in.When i installed the engine in truck & started it,it ran about 20 minutes & ate the cam lobes on #6 intake and exhaust.After taking the engine to local machine shop their findins were the bore was too big for pistons.The rockers are supose to be the comp cams magnum 1.6 but i dont see the "cc" on the back of them.I believe they are some generic brand.The reason the engine was sent back for the re-ring job was because it smoked at idle.The spark plugs were wet with oil.Speed-o-motive said the carb was too big causing ring wash.If this is piston slap will it hurt anything?I have adjusted valves but it still makes noise when cold.  

It is not a "too big" carburetor that causes fuel wash down but typically a ruptured power valve or malfunctioning needle/seat.  Black smoke will be visible.  Gas works like a cleaning solvent literally washing oil off the cylinder walls allowing the rings to run metal to metal.  The rings lose their ability to seal including oil control thus the oil wet spark plugs.  The rod and main bearings are also typically wiped to copper.

The block is honed to give the rings a fresh surface to seat.  KB states in their catalog piston to cylinder wall clearance for hyper-eutectic pistons is .0015-.0045.  Re-honing typically removes .0005" material so it is highly unlikely the "bore is too big".  Piston slap is easily diagnosed as the distinct knocking noise is made only when the engine is unloaded like decelerating down-hill with the throttle plates closed.

Speed-O-Motive uses Comp Cams rockers as well as other brands such as Crane,Crower and PRW but a review of your invoice will note the brand.

Does the engine still make noise after your local shop repaired?  

yes the engine was bored from .030 to .040 by the locall shop due to when bored at speedomotive the .030 bore was too big causing rings to not seat. The other problem i found was the block decking was not done correctly.The pistons were hanging out above the deck all at different heights,#1 was out .010 which was the highest.As for the rocker arms i have seen comps magnum roller rockers on my buddys engine that have the "cc" on them whitch i assume means comp cams. I was very unhappy with the work speedomotive did.I thought i was getting a quality engine not one that had to be rebuilt 3 times before it had 100 miles on it.Speedomotive built it when i orderd it,put it in & it smoked ,sent it back they reringed it put new bearings in it dynoed it got it back complete ,put it in truck ran 20 minutes ate cam shaft.Speedomotive told me i did not remove distributer and reprime oil pump ,the engine had been tuned on the dyno have dyno papers showing pulls.I took this to mean if engine sets for 2 weeks you better pull distributer & reprime & i know that is "bull". I currently have $7500 in this engine, speedomotive still would not stand be hind their work,wanted me to pay return shipping again for their mistake after the cam issue.Found out by looking at invoice they changed one lifter because it looked bad.Comp cams says never do this with flat tappit cam after the cam has been ran.I'll end this by saying I will never use speedomotive again nor refer them to anyone else.