Yeah, what ↑he said↑. Guessing at a problem usually doesn't give a satisfactory, complete, or cost-effective fix. There are many, many causes for rough idle beyond the obvious ones. A leaking EGR valve could cause a rough idle, but so could many other things. How many miles are on this engine? How exactly did you do your valve adjustment? Tell us about the procedure you used. Cam timing could be off due to timing chain stretch. Ignition timing could be off due to vibration damper outer ring slip. Could be vacuum leaks at the manifold-to-head junction. Could be exhaust leaking through a crack in the intake floor (blocking the EGR valve won't help this). Could be vacuum leaks elsewhere in the engine bay. Could be a carb problem not addressed by the rebuild. Could be weak ignition caused by a weak spark box or low primary voltage caused by high resistance in the wiring harness or by weak alternator output at idle.