In this paper, a novel asynchronous circuit design for reliability is presented. A special technique that enables fast forwarding is applied to the circuits, and the forward transition improves to less than 2. The handshaking process and cycle time of the asynchronous circuits are analyzed, and its performance and functionality under physical fabrication and external temperature variations are evaluated through Monte Carlo simulations in 65nm technology. The asynchronous circuits are compared to the static and domino logic circuits to assess their delay variations and functional success rates.