You can check the LAX site at:
http://www.lawa.org/fsw/default.aspx
Just do a search for Terminal 2 and you can see the scheduled arrivals at any given time in the day.
Remember that domestic flights and Air Canada flights from many Canadian airport pre-clear in Canada so they won't be going through immigration/customs.
When I went through around that time last year (coming in on NZ from LHR), it was pretty busy.