anyone have the same problem?

i will some it up to make it short and sweet... 98 150 4.2 started knocking bad pulled out #4 plug unhooked coil, cranked it shot out some coolant... sounds like Hydrolock that the 97-98 4.2s are known for.. This is what it seems like to me, does anyone else feel this way? also what would cause the oil to look like it needs to be changed even though there is only 100-200 miles since last change. also rare is it for the flywheel to crack or break on one this new that hasnt been beat on and just driven like it should? thanks in advance

blown head gasket or cracked head