Need some help: Tachometer displays four times 3.200k @ 800RPM

I assume you have a good ground on the tach, and are using the coil (-) as the tach trigger. Problems of over reading, may be that the tach is seeing multiple (4) triggers for each ignition event. Tachs have an input circuit to attenuate and clip, followed by frequency to voltage conversion, to drive the gauge movement.

To separate a possible ignition problem from tach, you could possibly test tach with a 24 ac transformer. They are fairly common, a doorbell or hvac transformer comes to mind. At 60Hz, there are 3600 pulses / min, but divide that by 4 since a V8 puts out 4 pulses/revolution, so a V8 tach should read 900 RPM. Test that, if tach reads 900, good.

The next step for me would be use a high voltage probe 1-2kV and scope to view the coil (-). The scope view will provide the ability to identify multiple triggers. There may be issues in wiring, including ground that is retriggering, such a problem may lead to early failure of ignition, and poor high RPM performance.