HELP Please !!! - Water in the Oil

I changed the oil on my 340 engine four days ago and the oil looked fine. The wife and I went cruising a couple of nights ago and when I got out on the Freeway I punched it and cloud came from the exhaust, but the heat was good and the car ran fine. Yesterday, I checked the oil and the dipstick was completely covered in white foam . I took off the valve cover tonight an they are completley covered in white foam.
My thoughts are head gasket or cracked head.

Any opinions on what to look for would be appreciated.