I think the last year for the 383/335 was 1970. By 1971 Chrysler dropped it to an advertised 8.7:1 comp ratio, and was rated at 300 gross/250 net horsepower. Makes sense that a heavier car, with less gear and just 5 extra horsepower is the slower of the two. Converter stall also plays a role here. A smog 383 with a 11.75" converter doesn't seem like a combo that would launch better than a smog 360 with the smaller 10.75". But....... This doesn't completely account for the huge difference in ET.
I would say the driver and tune play the biggest role in the ET/mph discrepancy. An inferior driver in a car that still needs bugs figured out is the only explanation for a full 2 seconds and 10mph difference at the finish line.
I don't think this makes a case for 383 being doorstops.