I called them yesterday. Last year at 1st March they took to 414 however some people turned it down
and by September they had offered to 411 BUT not everyone with 411 got a place, it depends on where you live. She thought that someone with 415/6 should stand a reasonable chance this year but no guarantees as they were not really sure of the impact of the change in 420 to 421/2/3.
Hope that helps
The change to 423 will make absolutely no difference. All it it does is distinguish between the lower few of those previously scoring 420 and above.
As far as I am aware, results have always been standardised to 141, Kent simply rounding all the very high scorers down to 140 for neatness. I can only assume they have returned to 141 this year just in case Judd is oversubscribed with 420 scorers.
What it does show, is that many school staff do not know how the standardisation process works, and you have to be wary of what you are told.