You're running 3-4 psi more in the first video and I can tell you're running a different supercharger pulley. Did you test your valve spring theory without changing any variables?
Both runs are on a 3.0 pulley. It was just way colder in the first video. Obviously, you can see that the valves floated.
2001 GTP Drag Car - XPZ, Tischler heads, Upsidedown M90 IC'd, e85, Gen V, 2.3 w/ 5%OD
2005 F350 6.0 - studded, deleted, tuned
2001 GTP - cam, headers, nitrous, stock trans - 11.83 @ 116 <$2k in mods - sold