Here is a pic of my old Smart Engine Analyzer dinosaur and engine test stand.
Made by Allen back in the 80's for emissions certification.
The O'Scope was optional but is great for tuning as you may run primary and secondary ignition patterns.
It will also show up bad ignition wires, weak condensers, bad spark plugs and more.
Takes a while to learn to read the pattern but no time at all to spot one that differs from the others.
As a set I get to fully tune an engine before putting it back into the car, find and fix leaks, etc.
This is an OLD unit but even it has a menu to help you troubleshoot problems.
I can actually set it up for most pre-OBD cars and even antiques can be run on it in Manual mode.
I am sure the new units are capable of a lot more than anyone will use for pre-OBD cars but the basic functions of ignition, alternator, voltage analysis are nearly priceless on their own.
I need to look into these some more but may already have a small suitcase size Allen unit I had forgotten about.
EDIT to add, Most of those advanced functions such as throttle position, air flow, and camshaft will only be applicable to EFI equipped cars with OBD.