How to build a 13 second 340 Duster

I have a 73 340 Duster. I am using a 360 with Eddy heads, hughes 230/236 hydraulic cam, eddy air gap, holley 750 dp, TTi headers. Has stock converter and 3.23 gears. Rear tires are only 225/60-14.

I have to roll into throttle to keep from spinning tires. Ran 14.011 @ 101.26 in Las Vegas. My MPH says the Duster should run low 13's or faster if the car was geared/tires.