Whats the best time for a factory stock duster 1/4 miles ??

Howdy! I know this is an old thread, but I just found this board while looking around for 340 info. I had a 73 Challenger with a 340, T/A heads, 650 Holley, you name it, that motor had it. 3.23 in the back, and I could pull a 13.1 with it. Would have been faster with better tires, I'm sure. The guy I sold it to wrapped it around a tree two weeks after he bought it. :( But the motor might still be lurking about somewhere in central PA.