Distributor, distributor drive gear / Timing

I have a 72 Plymouth scamp (106,000 mils) V8 318 5.2 L (bone stock) that had been sitting for 16 years when I got it.
(The vehicle ran fine when it was parked 16 years earlier.)
I have been working on it for the past three years as funding $$$ has become available.
New fuel tank,
fuel line,
fuel pump,
fuel filter,
new / rebuilt Carter carburetor. OEM 2bbl

Here's my issue, I got her up and running beautifully. With new points, condenser, distributor cap, rotor, plug wires and plugs. Had the timing set, and everything was running beautifully. I even drove her into town a few times. The only issue was kind of like a misfire every now and then at 65 MPH or so. (like a hick-up or air bubble in the line) about one seconds long. (No big deal)

Then one day she was getting very hard to start / wouldn't start. Backfiring, Spit'n & sputtering like she was running on four cylinders or had bad gas. (As if the timing was off)

I called a Mopar guy over to take a look at her, due to she was stranded in the middle of my driveway now and wouldn't start.
He said "hop in and crank it up". I said "she's not gonna to start".
And sure enough she started right up. (He made a small adjustment on the distributor.)
Adjusting the timing.
Then he told me that "this particular year model has Teflon / plastic teeth on the upper pulley / gear, and sometimes they will start chipping off allowing the timing chain to get sloppy and throw my timing off."
So, to make a long story short. I replace the timing chain and pulleys with a new set.

She will start up and run. (but not very good) I tried to set the timing, (with a timing light) but the timing mark is nowhere in sight.
This leads me to believe that my problem might be the (distributor) / distributor drive gear.
I have a lot of up and down play on the main distributor shaft.

I have NOT pulled the distributor, because I don't want to miss this project further.:banghead: