Clean the oil off the cam and lifters that was put there by the manufacturers with solvent. Then wash both cam and lifter faces with dishwashing detergent and hot water. Then sit down with a can or jar of molybdenum disulphide (that black, thick grease that comes with the cam) and massage it into every part of the cam and lifters that will mate up on assembly with your hands.
Add a bottle of GM EOS to the engine oil like 327NUT said and install some worn-out stock valve springs in the heads. Use them for break-in, then change them out for the springs the manufacturer recommends to run with your cam and lifters after you've run the motor about 50 miles. Use a top quality racing motor oil that has the additives in it that have been taken out of regular oils.
A little caution now will prevent tearing the motor down to clean it out and buying another cam and lifters to do the job again.