problem with deistributor

The distributor is usually driven via the distributor drive shaft which has a replaceable gear attached at the bottom. The gear is keyed onto the shaft and is critical in the timing sequence. When the number one cylinder is at top dead center "at the top of its compression stroke", the rotor mounted on the top of the distributor shaft must be pointed towards the number one spark plug connection on the distributor cap. Removing the one bolt should be enough to allow the distributor assembly to be lifted up and out of the engine. Try giving the shaft a little rotation while lifting up and the drive gear on the distributor shaft bottom should disengage from the cam shaft gear that drives it.

the timming belt is bad or broken. even if you can see the belt is still in the pulleys when they get old the drive teeth can be sheered off so the belt does not turn the rotor.

There is no timing belt. As far as getting it out of there, soak the base with carb cleaner (varnish is holding it in place) and just keep twisting it as you pull. There is only the one bolt and decades of crud. It may take several applications and a few ours of soaking but it will come out of there. Follow what GregPowell said. I have a concern that the oil pump may have frozen (which I've only seen twice in my career - wire brush strand stuck in the gearotor). I know that there's virtually no lubrication in a distributor shaft and yes, the gears and pins do fail. Best option is to replace the distributor with a re- manufactured unit. Why not go electronic while you're in there? NAPA has a nice setup available and you'll never have to set the timing again!