JPC has now released a TR6060 crossmember for the S197 and S550 chassis.
The Ford OEM crossmember for a GT500 are now no longer available. These crossmembers allow for easy swap of a TR6060.
Built out of 1/4" steel they are setup to be more durable then factory. These also use a factory OEM transmission mount and are compatible with the GT500 style exhaust hangers.