Valve lash

To me, 0.006" is a lot to take out of the lash for alum heads. My experience has been about 0.003".

However, this is so easy to check, it beats me why more people do not do this simple test that will give an accurate number for their combo.

Have your tools ready. Get the engine to operating temp & then switch off. Quickly remove a valve cover & find a loose rocker. Measure the lash & record it. Come back in the morning when the engine is cold & re-measure. You now have your hot-cold difference.