I work the north 40 flight line ops, parking.

The cessnas will be at the west end of 9/27, north and south of the
runway, but as mentioned, you need to make a reservation with the folks
who are organizing it. The mass arrivals are Saturday afternoon, with
the cessnas scheduled to arrive at 2 times, 2pm and 3pm. There are also
the bonnies arrive at 1PM, and mooneys at 4PM, so anybody else may well
want to avoid arriving saturday afternoon if at all possible!!

With that said, it does take awhile to fill up the north 40 camping, so
if you arrive through sunday, you should be able to get a space.

Personally, I think they are way overestimating the numbers of cessnas
that want to park in the reserved areas. 500 planes is a heck of a lot!

John