A stock 283 with any mild cam should get you in the 15 second range. My std bore 283 in a 3400lb car with me in it ran 15 sec with 3.55 gears/4 speed and a cam with about a .470 lift. the 600 holley is perfect on mine, it does better than the edelbrock 600 I had. Put together what you have and run it, it's already paid for. If it is not working right you can easily make a cam change latter.