which engine block give more power ,is the long block better or short/normal block better?

Answer 1

Long block and short block are usually used as description of rebuilt engines. The "short block" refers to an engine rebuilt with block, crank, rods, pistons cam and related rings and bearings.
(there are no heads)
The "long block" is a rebuilt engine in which the heads, valves and springs have been rebuilt and assembled as well.

Answer 2

"long" and "short" do not refer to the size or length of the block... these are terms that refer to replacing or building an engine. A short block is the block, crank, pistons,etc, but not the heads, intake or exhaust manifolds, starter,etc. This is good if you are replacing a cracked block or building a racing motor. A long block is also sometimes referred to as a crate motor... that is one more complete and ready to put in the car or truck and have running in a short time.