I posted a message about a month ago about a pinging problem that my engine was having. The recommendations was to check the timing since that's really the only thing that may have changed. Well, it looks like that's the problem, but I'm having troubles getting the distributor to rotate so that I can make the adjustment.

If I understand the process right, there's only 1 bolt that has to be loosened in order to rotate the distributor. I have located and loosened this bolt, but it won't budge! I carefully used a pry bar to try to break it loose to no avail. Has anybody had one of these get fused in place? Is there something else that I'm missing? If I remove that bolt, should I be able to also pull out the entire distributor unit in case I need to adjust the distributor gear alignment?

Currently, my timing is set at 8 deg. which, according to the thy holy book of 200 series bricks, is where it's supposed to be. However, my car has over 360K miles on it and has never been rebuilt, so it may be different now. Thanks.