OK... This will make a huge mess.
With the shortblock in the car....
Pull the oil pump and front case, leave head off, Rods/pistons, crank in block
1 gallon of diesel fuel/kerosean, assortment of brushes, and a good gasket scraper.
Make one brush an old tooth brush, and a parts washer brush.
Stop by a gun shop, grab to rifle nylon or copper brushes on long handles 20ga and a .22/.25 cal
1qt purple soap
2 cans brake clean
1 can WD40
1 Roll blue paper towels
Wine bottle cork
Air compressor w/ hose and blower nozzle
Read these links
Head gasket Repair- How to clean the block deck with the pistons installed.
How To Final wash an Engine Block
Remove all the old gaskets
Scrub the inside the block around the crank, use brushes & diesel fuel
Run the 20ga brush down the main oil galley
Use the .22/.25 cal in the vert oil passage to the head
You can also scrub the outside of the block with this
Now hose everything down, inside and outside the block, crank rods everything! Flush the oil galleys with water till they run clear.
Now with purple soap spray it all down and scrub some more. This will also remove all the residual oil film left from the diesel fuel.
Rotate engine as needed to get under the pistons.
Blow dry the cylinder bores and the HG surface, get some WD40 or a wipe of motor oil on the bores to prevent rust.
Now touch up clean any small dirty/oily spots with the brake clean
Spray WD40 on the inside the block crank area to help prevent rust.
Now flush the vert oil galley with brake clean, and blow out with compressed air.. it will come out where the front case mounts.
Now take the wine bottle cork, and wittle it down so it fits very snug into the main oil galley on the front of the block, if it has a slight leak, it will be ok.
With all the cleaner, solvents and water that has been run thu the oil galleys, some has made it between the crank bearings, both main and rods, this all has to be displaced to prevent rust there.
Now pour oil down the vert oil passage that feeds the head, a small funnel, or the nipple top from a gear oil bottle will be handy at this point.
A buddy to help would be great at this point, or Mom, Dad, little sister.....
Start "Burping" the air nozzle down the vert oil passage, this will help push the oil on to the bearing surfaces, be carefull not to blow the cork out of the front of the engine.
As you do this, have the helper slowly spin the crank over, untill you see the oil drip from between the side of the con rod and crank. and come out of the oil squirters if your engine has them.
You will have to stop and refill the oil galleys as needed, 3 or so times.
Once you start, you can not stop and let sit, rust will start to form on the crank bearing surfaces
So no letting it sit over night till you force a good amount of oil over the bearing surfaces!
Now if you have the short block out of the car, you will follow most all the above, with a few changes.
You will remove the rear oil galley plug in the back of the block.
Insted of Diesel fuel, get a can of Easy-off oven cleaner (yellow can) or Easy off BBQ cleaner (black can)
Have acess to a pressure washer is best ( Car wash)
Welcome to the "shade tree" way of cleaning a short block......