Okay, I hope that title got your attention....
Started off with preparing for a headgasket change.
Got the head off and came across this crap, looks like coolant mixed with the motor oil.

Larger picture:
https://i.imgur.com/gIjq2.jpg
What do I do? What is the preferred method and items to use etc; to clean out the block?

 

...............bump

 

Send it out and have it hot tanked.

 

purple power and a pressure washer if ur not going to hot tank it.

 

Been reading up on Purple Power and it seems like people have problems with it could be lack of dilution or there is something wrong with it.. as opposed to Simple Green.

If I were to Pressure Wash it, should I worry about my tap water getting in, and when/if I do, do I just open up the oil pan and let the Pressure Washer / Cleaning Chemical (simple green, purple power, whichever I end up using) drain out?
I've already drained all the oil and I don't plan on taking the block out any time soon until I do a swap in the later months. I'm just changing my headgasket but want a clean surface and work area when putting things back together so no more crud gets in them.

 

I never noticed you were just doing a headgasket. Dude, that engine is done for outside of a rebuild. If you got coolant in the oil expect to spin a bearing soon.

 

Clean your cylinders out and the gasket surfaces and put it back together. Then buy some of that radiator flush or just use something like powdered dish washing detergent. Put it in your cooling system, run until hot, and dump. Keep repeating that until you are just getting the detergent and water out...then keep repeating with just water until it dumps clean.

Also change your oil before firing it up. After running it to get it hot the first time check the oil...if it isn't clean (any foaming or evidence of coolant) change the oil again the same time you do your antifreeze. Keep flushing the oil and coolant until clean. If the oil is really bad you can put in a half quart of Marvel Mystery Oil to help dissolve the junk in there.

And yes...it can take a while....I've spent a day doing that to get an engine cleaned out. And you better hope you didn't wipe your bearings before you shut it off or you'll notice the engine loses oil pressure when hot.

 

So pretty much let my engine clean itself out? Hmm, what do I get to clean it before I reassemble it, recommended items? Simple Green and an old clean rag?
How about oil and coolant too, get 2 gallons of 50/50 antifreeze and 3-4 liters worth of motor oil?

 

Don't waste your money on premixed antifreeze. Ever notice how a bottle of premix goes for the same price as a bottle of straight fluid?

 

Dude I just did a head gasket with a rebuild on my y7 and it looked the same just wipe the **** down with a terry cloth and blow out the the rest with an air hose before assembly then when it's back in the car just run a fuel system cleaner or sea foam the thing.

 

Like stated above get it hot-tanked and if you plan on pressure washing it, i would recommend finding away to get distilled water instead of tap.

 

The OP is doing a headgasket, not a complete engine pull. READ.

In response to your dilemma, if you're content with just doing the headgasket, just give it a good rinse out with some soap and water. The coolants job is to cool your engine, I don't think it cares if there's a couple bits of debris floating around. The only thing I could see happening is clogging your heater core, but that's preventable and easily fixed.

Don't take the crud in the coolant too seriously.