I need some serious help or something..

You could have a bad headgasket or TB gasket and it is ingesting coolant? I would check those first before you assume the block is cracked.

I doubt the block is cracked. If the engine wasn't burning coolant/oil before it was taken apart, then there shouldn't be any reason why the block is cracked. I'd take a look at the intake gaskets/head gaskets first, and be sure that your head bolts were torqed down properly and with the proper sequence before deciding to throw a whole other block in the car.

Also on those lower intake bolts, the manual says to torque the bolts down in 3 steps, it was more like 6 or 7 times for me until I got the specified torque spec on all the bolts. Some tend to loosen as you are going through the sequence.

Good Luck!

The EGR spacer has coolant lines going to it, and if it's leaking that can be a source of the white smoke, but I don't see how that could contaminate the oil unless it lays in the cylinders for a very long time and leaks past the rings...Have you checked the bolts on your water pump to your timing cover to make sure they are tight? That will contaminate the oil also if those water ports are leaking. Damn...I dont know you've got me curious now...lol...I'm going to try and think of some other things it could be...lol

Check the head gaskets by doing a compression test and see if the cylinders hold compression. If you have a leaky head gasket then the cylinder(s) wont hold compression...by the way did you put teflon tape/pipe dope or silicone on the lower head bolts when you reinstalled them? I dunno just an idea...lol

If you didn't use teflon tape on the lower head bolts then this is your problem. The lower row of head bolts go into the water jacket and without the teflon tape you get a coolant leak. I can almost guarantee this is your problem. You might be able to get way with pulling the lower head bolts 1 at a time and puting some tape on them and then put it back. To do it right you should take the heads back off probably. Good Luck.

Yes pull the lower bolts out one at a time, starting with the center one and working out. I was bolting my heads on when I realized that I forgot to put thread tape/pipe dope on the lower bolts, and didnt realize this until after I torqued them down to spec. Wasn't no big deal though I hadn't run the engine yet, and it was still torn down to the heads yet, so I took them out one at a time, and I used a LOT and I mean a LOT of blue permatex silicone on the bolts. Someone on here reccomended that to me, and to use ultra black permatex, but the blue worked fine for me. But yeah, when you go to put the bolts back in, torque them right to spec; no need to do it in steps. It would be a good idea to go over all the bolts again in the proper sequence just to be sure that they are all torqued to spec. If you go with silicone, just be sure to use lots of it and let it dry some before you start the engine.
You can do what you want though, teflon thread tape or silicone.

As for the oil, I have heard of people running a little bit of kerosene with some fresh oil to clean out everything. Not a lot though. I filled my oil pan with kerosene when I took the timing cover off, so that any old small pieces of gasket material that fell in the pan would wash out. Some kerosene acutally layed in there and after I filled the car up with fresh oil again I could smell it in my oil. And when I drained my oil after my first startup, the pitch black oil that came out looked like something I could pave my driveway with only after running it about 30-45 minutes...lol...so I guess it cleans very well. Another alternative is to just drain the old oil the best you can, fill it with fresh oil and let the car run for a little bit, let that drain out real good and refill it again, then you are good to go.

Good Luck!