Ok so I just recently did my first head gasket repair on my 1998 F250 5.4. I have to say it was a lot of work. I bought all new gaskets. Some friends asked me if the truck ever got hot or ran hot. They said if it did, then you need to check if the heads warped. But it never ran hot, so I never considered getting the heads inspected. I also did not replace the valve stem seals because I was afraid of losing the timing. I cleaned everything and I put the head gaskets on dry. I got new bolts and torqued them to 30lbs, then 90 degrees and then another 90 degrees in the pattern to tighten the bolts. I put the entire engine back together. Then I turned it on, it sounded great!! I had never heard this engine idle so steady. It ran good, and felt good while I was driving. It ran for 200 miles until the WHITE SMOKE came back. Then I checked the oil and sure enough, the water had mixed up with the oil. So I guess, it was never the head gaskets that were bad. I was going to use that blue devil gasket sealer but then again, I wanted to repair it the right way. I just took the engine apart again, but this time, I did it way faster, I knew every bolt size on this engine so I just got to work. When I got to removing the engine heads, I started to notice that on the head bolts, some of the bolt threads were dry and white, while others had oil on them. It made me wonder if I bolted the heads on correctly. I am now going to take the heads into a machine shop of inspection. I am also going replace the valve stem seals. I should have done that the first time. So I am here trying to see if anyone has any suggestions as to what might have gone wrong with my first attempt of repairing the head gaskets. When I cleaned the surface of the heads, I used 150 grit sand paper with a block but I didnt grind it, just lightly cleaned it then followed up with 400 grit. I am also including some pics of the valve covers, as to the way I found it after taking the engine apart for the second time. The pics are the valve covers, the bolt threads and the bottom of the heads. Again, I am hoping someone can give me some advice as to what I may have not done before I put everything back together when I get my heads back. On the positive side, I learned a lot about engines and I am no longer intimidated by them. Thank you guys,

 

Crap, something is cracked
Most likely the block