Granger and Dahntay Jones can do a decent job on Bron and Wade.I think the Pacers are athletic enough to help defend the two.
Then you have Hibbert on the inside deterring shots at the basket. When he goes out, Psycho T and Amundson give great effort defensively and rotating to help off the bench. Even Hibbert himself does a decent job rotating and hedging for someone his size.
And really, besides those two, who is scaring you? Bosh is a glorified role player playing alongside Bron and Wade. West on the other side, provides the Pacers with the same thing Bosh gives Miami.
If you asked me before the playoffs I would have been surprised if the Heat lost to the Pacers. But from the little Ive caught of them in their last series, Ive changed my opinion on this team.