Truck Titled as "Automobile"??

[socalkevin68]

Hi guys...hope someone can straighten me out on this one...
Ok...i'm trying to purchase the correct black and orange ca. plates for my truck (presently has the "incorrect" blue plates). I'm bidding on some on ebay. but as I look at the diff plates up for auction....i'm seeing..ok to register on truck..and some say ok to register for car.....
Here's the kicker...my Ca. Title for my 68 long bed c10 says "Automobile) in the left hand corner..the under that is says Body type model "HSCR"
I have no idea why it would be registered as a automobile..and what hscr means...
Even more confusing is the issue with plates being ok to register on car or truck..Should I look to bid on some plates that are ok to register on a car or truck......
thx if anyone can help.
kevin