Ka-Thunk - noise over bumps

OK, I've installed my new OME suspension. (See http://www.tacomaworld.com/forum/su...talls-full-ome-kit-rear-brake-lines-pics.html)

I've got a fairly loud ka-thunk when going over bumps. I can rattle it pretty good at low speed on some parking lot speed bumps.

I'm pretty good at diagnostics, usually.

So, what are the questions I should be asking myself in order to narrow down what the problem might be?

for example:

front or rear?
left or right?
noise on compression or rebound? (though actually, I'm not sure I can tell that one)
etc...

Then, what are some likely causes, and how can I test for them?