I have pulled the heads off of probably hundreds of engines, but nothing I try will get the head to break free on the F134 in my CJ5. Yes, I am sure all the head bolts are out. I have driven a thick paint scraper / putty knife between block and head at various points around the head, I have whacked it with a block of wood and hammer each side, front and rear. Still stuck fast. Before I gave up for the day I bolted a chain to the head and put some good tension on it with my engine hoist. That did break the seal toward the rear as some coolant began to drip out. I figure to leave it hanging by the hoist for a day or two to see if it pulls free. I am pulling the head for valve work.