You might be able to dip into the 11's if your combo is 100% working on a great weather day other wise I think your going have to change something. We have raced a Duster 3200ish lbs, dedicated race car, but not all chopped up for 15 years now with a 360. Dana 60, 4.56 gears, 30" tire, 727. The compression has always been 10-10.5:1. We've ran .a 533/.533, .519/.524 hydraulic cams, .528/.528 solid cam. We picked up a good bit when we went to a 8" 5000 stall convertor. All engines were shifted at 6,000, used a Victor 340 intake with a 750 Holley. We've ran steel X (I think X and not J but could have that backwards), Edlebrock and Trick Flow heads. We ran the Edelbrocks the most and that combo was typically a 11.60-11.80s combo, best it ever went was a 11.51. Trick Flows we only have a few runs on but ran about a tenth quicker than the Edelbrocks. The steel heads ran 12.00-12.20s. We used to have cheap hedman headers on the car, but have since put Dougs 1 5/8 headers and with a 12" glasspak muffler.