Used a wood block and one sound rap with a hammer and it came loose. Turns out the valves are all OK in the original head and that there is some scoring and cylinder wall erosion at the top of #3 cylinder bore(motor is toast). This 87 xj was manufactured in the fall of 86 and came out of the factory with the distributor intstalled one tooth off. I bought the car when it was 8 years old and had 60000mi on it. Every third of fourth start it would shake like crazy and act like the starter cut out in the middle of the start cycle. It took me a year or so to figure out what was wrong with it and since I installed the distributor correctly it has run great. It is my opinion that on those rough starts, the spark jumped ahead to the next cylinder, ignited the mixture way to soon before TDC, causing huge pressure in the cylinder and eventually cylinder wall erosion as the hot gases leaked past the piston rings. I am hopefull that the dealer where I bought the head will allow me to return it and I'll buy a Mopar remanufactured engine. If not I guess I'll by a short block and install my new head on it. Thanks for all your collective help, this is my first foray into tearing engines apart.