I was wondering what's the difference between a big block and a short block? The block is where your cylinder and pistons are right? and the head is where the valves are if i'm right.

thanks

 

Do you mean short block and long block? A short block is the block, crank, rods and pistons(and sometimes a cam), whereas the long block is all that plus heads and sometimes an intake, plus valvetrain stuff.

Small block and big block is an engine size issue, and is generally determined by bore, stroke and bore spacing, though lately we are seeing some large small blocks such as the new LS7 from GM, a 7.0L(427cid) that is classified as a small block.