It wont start

My car wont start,

it is a series 2, 4.2 L with a 3ohm coil (no resistor installed).

I replaced, wires,
condenser,
points,
checked spark plug gap,
checked fuel pressure, it has about 3.0 psi
, checked the white wire on coil (negative)- it has 12.5 volts going to it.
Checked continuity of black white wire to distributor, all good.
Checked Coil has 3.0 ohms of resistance, it has.

There is power to the coil but when I turn the engine over, no spark. I'm used a timing light to verify if there is no spark.

I've also replaced rotor and distributor cap as well.

There is no spark at the plugs. What else can I check. How would I check the coil further?

Ready to get a mechanic involved but would really prefer not to.

Any help is much appreciated.