The first 20 minutes or so of run time is critical for the cam lobes/lifter faces. Coat the lobes and lifter faces with black moly which is usually supplied with the cam when you buy it. It's a thick extreme-pressure lube used to break-in the cam. Any cam grinder can supply it if it wasn't in the box with the cam. I also add a bottle of GM Engine Oil Supplement to the oil before firing initially. It contains moly and can be found at any GM dealer at the parts counter. After the 20 minute break-in, dump the oil and change the filter. Add fresh oil and include another bottle of GM supplement. Run that load of oil for about 300 miles, then change oil and filter again. You can continue to add the supplement to the oil changes after that or you don't have to if using a good quality oil. That's how I do it and I've had good luck with cams over the years.