I would either confirm that by removing the inner spring the rate is very similar to stock or use old ones. I would coat the cam lobes and lifter bottoms with cam break in recommended moly lube and add a couple bottles of GM EOS. I would also make sure the engine oil pump is primed up and ready to go. There's recent stuff in here on oil as well. Seems like the 20W50's are much better for break in than the 5W30's for example.

Kitz