The actual definition of a long block and a short block varies depending on who you are talking to, but typically a short block is typically just a block with the rotating assembly (crank, rods, pistons, cam). The definition of a long block is a little fuzzier, but I consider a long block to come with all a short block has along with heads, intake, front cover, flywheel housing, flywheel/flexplate, intake and valve covers. Complete engine would be a long block with all wiring, fuel lines, injectors, accessories, etc.