Ford Repair: No Compression, ford f 250, rod bearings

Question
Have a 2003 Ford F-250 Super Duty 2 wheel drive 5.4. Lost compression in cylinder 4 on a trip two weeks ago..Came home sent heads to a machine shop. Pulled engine and put in new rings and rod bearings. Machine shop said there was no problem with the head. Installed engine and put heads back on. Started truck and still had no compression in cylinder 4. Pulled head back rechecked trimming chains still no compression. Got a used head put on and had 110 lbs in 4 and 90 in 1 2 and 3. Truck still missing. Pulled head again was told the head we got was off a 1999 and was wrong one. Wtih original head had 155lbs in all cylinders expet 4. Thought a lobe on cam my have moved so got new cam from ford and put on original head. Reinstalled and had 0 comp. in 4. I am now lost. I would think it must be in the head because with the used junk yard head I at least had 110lbs in 4. I have now spent over $1000 on this thing and still am no further along than when I started. Do you have any Idea what is going on here or what I may be doing wrong..? Thank you Steve

Answer
As you probably already know, the problem is in the head. We know that , because the wrong head even built compression. Buy the correct head, from Autozone, or Advance. Your looking at around 400 dollars, I checked. Probably less. You already have the new cam, and a rebuilt lower end. Of course, be sure and ge ta new set of gaskets, again. Never try to reuse a head gasket, no matter how long it has been on. Also, be sure the cylinder head comes with new rocker arms. If not, replace the rocker arm as well. If you have to purchase the rocker arm, buy it first, and see if it helps.