Harris,
The C-4 any time. Four of the people here have automatics and three have the C-4s with light shift kits in them and one has the C-6. The guy with the C-6 has complained about all the weight since day one. The local drag racers are running buit C-4s in their drag cars because of the weight difference and they take anything the C-6 will. As stated above, if you are concerned about resale the automatic may be a little of a problem to get as much for.
Ron
