Here's a link to the
DIS site's height calculator.
You put in your child's height and it gives you a list of the attractions that the child is too short for and what the requirement is.
For 43 inches, here's what came up (sorry it's kind of messy, but the formatting would not copy):
MGM Studios Rock 'n' Roller Coaster Starring Aerosmith
48"
Blizzard Beach Summit Plummet
48"
Animal Kingdom Primeval Whirl
48"
Blizzard Beach Downhill Double Dipper
48"
DisneyQuest Mighty Ducks Pinball Slam
48"
Magic Kingdom Tomorrowland Indy Speedway
52" (they can ride, but not drive until that height)
Typhoon Lagoon Bay Slide
52"
DisneyQuest Cyberspace Mountain
51"
DisneyQuest Buzz Lightyear's AstroBlaster
51"
Magic Kingdom Space Mountain
44"
Typhoon Lagoon Humunga Kowabunga
48"
Also note, EE is not on the height calculator, but the height for that is 44 inches.