your 5100s have five perches and you're on the second, right?
I saw another thread that the tacoma 5100s have 3 perches and you're supposed to use the bottom for that one. Figured I'd throw it out there as a possibility.
That seems a bit high in the front to me, too, although I don't have your setup (I want it, though).
also, what coils are you using in the rear? Unless you've got 906s, i think we should be seeing some rake.
As an update for anyone that cared, I tore these things out and dropped them down a perch. I'm now on the first perch and sitting at 23.5 hub to fender. Got rid of the vibration, but still have some noise. Gonna run it for the winter and do some more digging come spring time when I can afford to have it down. Thinking perhaps the front diff drop has the diff sitting on the cross member.