I think Santa Clara may still run original trains, doubt it but could be related to the new trains. I know development of the human body is taken into account too, which is why Demon and Shockwave had 100% identical trains but a 42 vs 54" height requirement. Perhaps someone somewhere along the line at PGA decided that Demon exerted to much force for someone in the 42-48" height range while SFGAm never worried about it and stuck with the manufacturer minimum.
though you never know, I know Eagle went from 36"-48" in one off season just so they could stop hearing complaints at Viper of "my kid can ride that but not this?"
Favorite Wood Coasters: The Voyage, Ravine Flyer II, Thunderhead, Balder
Favorite Steel: Voltron Nevera, Steel Vengeance, Expedition GeForce, Olympia Looping
Parks visited: 232, Coasters Ridden: Steel: 894, Wood: 179, Total: 1073