In my experience the cam gear is either good or bad. Sometimes the old fiber gears lose some teeth. When this happens the engine will not run at all. You could likely remove the cam gear as suspect because your engine runs.

If you have to check it... The timing cover will need to be removed. You will first have to remove the harmonic ballancer, and will likely have to remove the oil pan as well.

Runs and stops are usually fuel delivery/ carb problems.