With the milder hydraulic cam, and the long runner Cobra intake, the motor will be a low rpm torque monster. I had a similar motor (342", Holley intake, Comp hydraulic) in my car before the current configuration. First gear was basically useless, and second was still mighty squirrely. Huge fun factor though.
At the track, my short runner (4barrel style intake), and aggressive solid roller are better suited to open track usage, not sure how it would work out for autocross, as I've never done that. I'll be interested to hear your experiences once she's up and at it!