my 1964 barraucuda has no spark

At min, you need a meter, test lamp, jumper alligator clip leads

Turn key to run, measure coil + terminal to ground. Should have somewhere from 6--to 10V, not much lower and not much higher.

With meter clipped in place, crank engine with key and watch meter. While cranking, coil+ should see "same as battery" IE if battery sags to 11V when cranking, then coil + should be about same.

Disconnect coil wire and "rig" preferably a copper core wire--even a low voltage wire hung out away from metal--to a test gap or even a plug. Crank engine watch for spark

With key in "run" disconnect distributor connector. Take up harness end, and tap the bare terminal to ground repeatedly. You should get one single "snap" spark at the coil each time.

ECU box MUST be grounded. "Wiggle test" all connectors, and ESPECIALLY vigourously work the distributor connector several times to "scrub" the terminals. and to "feel" for tightnerss.