Engine Block Prep
Before an engine block can be checked for cracks and pitting it will need to be removed, the engine disassembled, and the parts cleaned. Make sure all the old oil is drained from the pan before removing the engine from the vehicle. Please note that removal procedures are different depending on the vehicle you are working on. They range anywhere from removing the hood and then removing the engine to pulling the transmission with the engine, lowering the engine from the bottom and on and on.
On most vehicles its best to leave the A/C compressor attached to the hoses (leaving the refrigerant in the system) and unbolting it from the mount or bracket. Fasten the compressor with a piece of wire out of the way from the engine to prevent any damage that may occur during removal of engine. The same is true for the power steering pump.
On some vehicles, especially vans the intake and or exhaust manifolds are removed just after the engine harness plugs and wires are dealt with. Removing an engine from a vehicle is 90% common sense and the rest is skill. Remember to be careful and follow the directions in the manual. Even if you know this engine well I suggest you keep all the bolts and parts organized and in the order of removal. This will pay off ten fold during the installation phase.
Once the engine is removed the flexplate/flywheel should be removed from the back of the engine and then the block carefully fastened to an engine stand using the appropriate bolts. Be careful not to damage the threads in the block when doing so. Patience goes a long way! 
It's a lot easier not to damage or strip something trying to save a little time only to have to go back and repair the damage once done. Reconditioning the threaded holes will probably cost you a lot more time.
Now that the engine is on a stand it will be much easier to work with. The belts and accessories and belt tension devices are removed and usually the harmonic balancer requires a special tool to remove; it may be pressed on.
Depending on the engine you will be removing either a timing belt or a timing chain along with their corresponding sockets along with the water pump. Remove the cylinder head or heads from the engine and place them in a safe area for the time being. An overhead cam type engine will have the camshafts in the head. Be careful some of these camshafts are actually two in one. They are held together with a set screw before removal. A special removal installation cam tool is used to carefully remove the camshaft from the engine.
Swivel the engine stand so that you can easily remove the oil pan (facing up) and be careful. A lot of manuals will tell you to strike the pan with a rubber mallet until loose. Some of these pans have been glued on and whoever wrote the manual never had to remove one of these things. So sometimes things aren't that easy and you need to use a screwdriver. Be careful not to damage the pan by 'going around' in several places tapping a screwdriver or some other sharp tipped object to separate the pan from the block. If the pan is creased you can pound it flat again with a small brass hammer. You will probably find a baffle and in some cases a balance shaft and an oil pump screen and in other cases the oil pump itself. Remove these parts as necessary.
Remove the rod bearing caps and always take note of the direction and the cylinder number. Keep them in order and take notice of any unusual wear. Now remove the main bearing caps and keep them in order as well. If the rod and crank caps are not marked mark them with a punch or awl so they can be placed back in the correct order. The rear main seal as well as the plate that contains it are removed and then simply lift the crankshaft away from the engine and place it in a safe place for now. Now remove the pistons from the engine being careful not to knick or damage either the piston, cylinder wall, or the piston rod. The final step is to remove the expansion (freeze plugs) from the engine. These should be swiveled by tapping on the edge of the plug with a screwdriver or chisel and then pulling it out with a pair of pliers. Mechanics have damaged blocks by not being careful when removing stubborn freeze plugs. Areas around freeze plugs, coolant jackets, water pump etc. suffer from corrosion over time.
