first off you need to define your actual goals for the car. how many miles are on it? you want it to handle better or just run hard? you auto or manual? what gears do you have?

going to a 383 is not just simply putting a 383 crank in it. it requires a complete engine rebuild with differnet parts to work with the 383 such as pistons, rods, bearings etc..

what is your budget?

 

whammer is right, but if you go the 383 route i would do a cam swap, headers, throttle body, high flow o2 sensor,and CAI. BTW are you gonna beef up the trans? Finding out how much power you want would help. Not sure what you specifically mean by make it go.