There seems to be a bias towards the south and west areas of Torrance. Please note there are perfectly fine (and highly rated schools) in the northern and central areas as well. As Katherine mentioned, check out the website Great Schools for more information. Be cognizant (as Tony mentioned) of the areas east of Western Ave that contain a Torrance post office address (usually 90502, but there are others), but do not utilize Torrance's city services (e.g. police & fire departments, water/sanitation, schools, etc.). Depending on where the address is, it could be considered Gardena, Harbor City, Lomita, Harbor Gateway, etc...all of which use City of Los Angeles' services. The only zips that are actually "Torrance" are 90501 (east), 90503 (central/west), 90504 (north) and 90505 (south)
My personal feeling is residential real estate (specifically single family homes) is unjustly inflated in price once you head west of Hawthorne Blvd, which I like to call the incorrectly perceived educational "divide". You're paying a premium to live in a house/neighborhood for elementary/middle/high schools that are rated a 9 (west of Hawthorne) versus an 8 (east of Hawthorne). Not really worth the extra expense for that extra point, IMHO. As it is, it's tough enough to find affordable housing in the South Bay for a typical family!