func_physbox problem

is there anyway to make something with one texture on it act like something with a different texture?

i know that sounds a lil weird, but when i was setting up a physics situation i was using dev-textures. when i now have the textures i want, the func_physboxs seem to have their own definition of gravity, resulting in them slowly falling, and physics explosions hardly pushing them at all, when before they would move easily 12-14 foot.
i thought maybe using the prop data field would help, but using settings in there either cause the brushes to gib, or has no effect at all.

small edit:
to test i reverted back to dev textures, and it went back to acting the way it was beforehand, so it's not that i did something else and forgot about it.

i was thinking it might be related to that, but that still leaves one problem - what keyvalues do i need to make it act like it has dev textures on it?