I'm positive I have an electrical problem/short causing an intermittent miss in the ignition. Not sure where.

I've changed the coil. That didn't do anything.

Tried swapping distributors. That didn't do anything.

I've changed the carb. That didn't do anything. Thinking it was the carb giving me a headache.

It does it all engine speeds but again it's not consistent.

I was told to check the electrical connection to the back of the alternator to make sure that the wire is tight and free of corrosion etc...that seems good.

The car is an original '68 Firebird 400.

Any ideas?

Thanks, Frank

What makes you positive it's an electrical issue? Do your lights and other electrics flicker? Do you have a multimeter? What is your voltage (running)?

Sounds like you've done a couple throw-parts-at-it things first. What about basic tune-up? Plugs, wires, careful wire routing, distributor cap, rotor, clean & set points, correct base timing/mechanical advance/vacuum advance, vacuum leaks, distributor wear & play, timing chain stretch, decarbon engine, all grounds and ground straps present and clean, voltage regulator functioning correctly, engine compression balanced within specs?

Need to know more details about what you're starting with and the condition it's in to really attempt to advise.

If after confirming all of above is good, and you're still 100% confident it's an ignition problem, then there is no better way to diagnose and find the problem than to find an old school mechanic who owns and knows how to use an Ignition Scope for a diagnostic.

X2. It's amazing what they can find out with one of those scopes.