It's used to set the point gap.
Yes, but the dwell meter is by far the best and easiest way on a Chevy.
A dwell meter is used to check the setting on a POINTS type ignition system, these have not been used in quite a few years, and for sure not as late as 1993.
The meter needs a dwell setting or scale. Otherwise it won't measure it with meaningful readings.
dwell dwell dwell
.020 If you have a dwell meter it is 30 degrees of dwell.
It was a tool used to accurately set the gap on ignition points. They don't get much use these days.
attach a dwell meter and set the points for 30 degrees.
Use a dwell meter to set the points at 30 degrees dwell.
This might sound confusing, but the positive lead to the dwell meter goes to the negative side of the coil -- the same side the wire to the points goes to, and the negative lead to the dwell meter goes to a good ground like an intake manifold bolt or coil bracket bolt for example. Make sure you read the dwell on the right scale for the number of cylinders the engine has, or make sure you have the meter set to the number of cylinders the engine has (depending on what kind of dwell meter you're using) or else the dwell readings and RPM readings will be wrong.
With a dwell meter you could monitor the dwell angle. If the dwell fluctuates the distributor shaft and bushings are probably worn out. The dwell should be between 28 and 32 degrees and not fluctuate.
My advice would be to set the points at .020" with a feeler gage to get the engine running, and then use a dwell meter to set the dwell after the engine is running.
Use a dwell meter to adjust the points to 30 degrees dwell.