engine issues, help please!
Don't take this as a fix for your problem, but this actually happened to me and I still have a chuckle when I think about it. :)
I was stationed in Germany in 1972 and bought this puke green 68 Mustang fastback, 302 cu.in., C4 auto, from another serviceman who was totally disgusted with his car cause he just couldn't get it to run right. Paid him $300 bucks and drove the Stang home. He told me he'd just had a valve job done and it never ran right after that.
Well, come Saturday morning, I fired up my new-to-me Stang, set the timing, set the Autolite 4300 4-bbl, checked the oil, water, tranny fluid, etc. I couldn't see the coolant in the rad, so I stuck the garden hose in and gave it a good drink, put the rad cap back on, and went merrily off down the street of the little German town where I lived. After about a mile, I noticed a LOT of smoke / steam in the rear view, so I pulled a U-ie and headed back home. Pulled the dipstick and noticed the same thing as you....major bubbly, cream colored, puke right to the top of the dipstick. Hmmm. The damned engine is full of water, this can't be good.
I decided I'd better have a good look around the engine compartment, and while doing so, noticed the tabs of the new head gaskets sticking out from the block.......... Hmmmm. Got out my trust tools, popped off both heads, flipped the head gaskets over so the tabs now pointed to the inside, top of the engine, instead of the outside, bottom, and put the heads back on.
I raced that Stang for 3 years after that and then sold it for a good profit, and never did have any overheating or coolant loss problems again. :)