Do you have any old/ used components "that probably work" that you can swap back in?
Some tests
1...Turn key to run, disconnect distributor pickup and take the engine harness end. Tap the bare terminal of the connector to ground. Each time should generate one nice fat blue "snap" spark
2....With key in "run" measure voltage at coil +. It should be somewhere between 6V and 10V or so. Much lower has a problem, if it is "same as battery" it means coil is not drawing current. That could be a bad box, an UNGROUNDED box, bad coil
3...If you have a tach connected disconnect it. If you have the radio supression cap connected to coil NEG disconnect it. It belongs on POSitive side
4...Connect meter to coil POS and crank engine. Reading should be high, near "same as" battery voltalge. Releasing key should drop reading back down to 6--10V in 2
5..Connectors can be a problem. Worst is likely dist pickup connector as there is no real current there. "Work" the connectors in/out several times to "scrub" the terminals and to feel for tight. Examine with a light for corrosion, oxidation, etc
6...Inspect dist look for strike damage on reluctor, shaft play and wear, rust, etc. MAKE SURE DIST is actually turning when engine is cranked.
