"barely .5"lift" seems pretty huge, no, humongous especially considering what these engines originally came out with I've seen timing chains jump on stone stock engines where the valves kissed the pistons
I had it happen to a Durango, 360 mag, brand new EQ heads that were supposed to be ready to run out of the box, but they had the guide clearance too tight, a couple of valves stuck on break in
(Stone stock bottom end, original cam it left the factory with still in place) and it bent a couple of valves on me
