Have you tried a different rebuiler, could be your problem right there, not the calipers, but the guy who's doing the rebuilding. I rebuilt mine and just bled the system. I just got the LT1 and T56 mounted today so it'll be a while before they're tested with power, but no leaks yet.
I got Maxima brackets from a dealer. A little expensive, but I couldn't find any at the local JY at the time.
- Joe