I was making a custom block model for a parachute to use in 1.9 with the new levitation effects. I made it first in 1.8 and it was fine, it was in the right position. I used falling sand to display it. When I went into 1.9 though, after changing the pack properties to fit 1.9, it was suddenly on its side.

I have attached screenshots of the same resourcepack (both in 1.9 format) from 1.8 and 1.9.