Question about cleaning coolant out of oil passages!

Hi folks!
I've got an old '66 Valiant with a slant six in it, I love this thing I've had it forever. About a year ago, I blew the head gasket on it; it was ultimately because I had a leak in the radiator and overheated the engine, blew the gasket. The motor was rebuilt probably 50/60,000 miles ago... so I opted to pull the head and have it rebuilt, but leave the lower end alone.

So, the past couple weeks I've been working on this thing on and off. New radiator. New hoses, new water pump; new thermostat. It's not overheating now.

On the other side, new plugs, wires, rebuilt head (none of the valves were really burnt before rebuilding it) by a reputable machine shop, they decked it slightly (can't remember the spec).

I'm ashamed to say I've NEVER adjusted the valves on this thing, but of course after rebuilding the head it was a necessity. I decided to try to clean up the oil of course before I started running the engine though..

So my question is, I found an old post by slantSixDan (love reading his stuff!) here talking about this, and I took his advice to someone else:

1. I drained all the oil, it had coolant in it obviously, and it almost looked like yogurt dripping out of the oil pan. Changed the oil filter, it looked like melted chocolate ice cream in that thing.

2. I filled it back up, and added some of that 5 min. flush crap that apparently liquifies the sludge. Ran the engine for 5 minutes or so (with the out of adjustment valves clacking away) and then drained it. Changed the oil filter. Lots of liquified mocha looking coffeeish colored oil/coolant/flush.

3. I filled it BACK up with fresh oil (getting expensive!), and poured a quart of Marvel Mystery Oil in. Why does this stuff smell like kid's wax candy? I wanted to drink it. Anyways, ran that stuff for about 15 minutes (up to operating temperature) with the valves clacking away.

4. Drained all that, and changed the oil filter AGAIN. This is my 3rd set of new oil in the last couple days. Looking at the oil I just drained (with the marvel mystery oil) it still kind of looks like coffee with cream in it. Nothing looks dirty per se, but it's almost got me scared that there's still a leak somewhere.

Looking in the radiator (new) all I see is fresh, clean coolant/water. Also when I drain the oil I end up with 5 or 6 quarts, which is what I'm putting in (5 new quarts, plus a quart of marvel mystery oil).

All the sludge is gone, but the coffee looking oil has me wondering if it's clean enough. The coolant level seems level too (the radiator cap is leaking a little bit, need to get a new one).

Any suggestions, or does anybody have any thoughts on this?

BTW, I adjusted the valves cold before I started the engine, but they were still clacking. I adjusted those suckers RUNNING tonight, that's fun as hell! If anybody hasn't tried that you ought to give it a shot, it'll make you feel like a man. Engine is running smoother than I can ever remember it running, and I don't even have the valve cover on yet... It's still got a little bit of a miss or something going on but I think that may be the carbureator or the year old gas in the tank...