Bass Trem Bar?

[bassrocker26]

so i was thinking about a whammy bar on my bass, but then i realized that you need the springs for it and such.

are there any specific bass bridges with whammy bar on them?

and also is it possible to insert springs into the body?

thanks

[WezV]

here are a couple of bass trem bridges

http://www.hipshotproducts.com/cart.php?m=...ct_list&c=4

http://www.wammiworld.com/7410.html

[low end fuzz]

do these things require a locking nut of some kind?