Can someone please explain what a "Small block" engine is, what a "429" is (or any other numbers for that matter)?

I've been curious about this and never learned about it!! Can someone explain what all this is and means? Obviously I know there are differences and preferences for each but I've got know knowledge of what it means...

 

"429" is the measurement of the car in cubic inches EX: chevy 555, ford 351. And the small block is different sizes of the engines. Anything over about 400 CI is a big block, usually. Under that is usually a small block like a 302, or a 289.

 

There are Small-block and Big-block engines. These families differ in respect to the distance between cylinder bores, but not necessarily in engine displacement since the latter is defined by bore and stroke.

While the big-blocks have been less commonly used in recent years, the small-block families have grown in displacement and have now reached a level that was reserved for big-blocks in previous years (up to 7 litres of displacement in a Corvette). Even though the technology has greatly changed, basic specifications have been the same for fifty years

http://en.wikipedia.org/wiki/Engine_block