Engine builders are always taking a bad rap from somebody... and they seem to be a temperamental lot to boot. You might post your questioin over on the FE forum as well (yes, I know you probably don't want an FE, but they all do get around there). I remembered this thread off the top of my head:
332-428 Ford FE Engine Forum: Another post about the 427/428 engines from Proformance Unlimited...