I never thought it made a difference whether the tranny was in D or OD? I thought the only difference was it won't shift into 4th if kept in OD?! (I've never heard that the line pressure applied on each shift would increase if the shifter was kept in D?).

Your times all look pretty close together, so I don't think it has anything to do with the shifter position..........it's all to do with your launch (mostly). Your times are between 13.7 - 13.9, @ 101 - 102 mph...................I've had times from 13.4 upto 14.1 on the same night, with speeds from 100 upto 106 (all based on my 60' time, which relates back to traction).