Ignition help needed for my 1973 454 C/20

[RPOZ11]

Was getting a bad miss thru the rpm range.
Started going thru the system.
Checked the distributor, had the wrong one in it.
Apparently this one must have been rebuilt by someone in the past as the mainshaft/top cam piece did not touch the weights of the advance.
What I determined was is that the weights were floating , causing the timing to bounce around.
Replaced it with a correct housing.
Now have what I think is the correct unit having a 718 CCW distributor cam.
The weights contact properly now with the mainshaft/cam piece.
I cleaned up this replacement distributor, greasing up the weight pivot points,
re-tightening the vacuum advance, and adjusting a new uni-point.
The miss thru the rpm range is almost gone vs. what it was doing.

Items replaced :
R44T spark plugs
Accel 8mm wires
New Coil
MSD Cap
MSD Rotor
A new uni-point point/condensor

Vaccum advance was the used original from the replacing distributor.
I checked it and it pulls & holds 17-20 on a Vacuum Gauge moving the breaker plate assembly.
Vacuum at idle from the port on the QuadraJet is 0; 15-20 thru acceleration.

Now my current problem :
I set the timing at the balancer, vacuum advance disconnected & plugged, at 8* BTDC; per the Sticker from GM.
Got the dwell meter out, calibrated it to 0, got it to 30* on the points, then checked & re-adjusted timing at 8* BTDC.
What it is now doing is falling on its nose, power surging to almost no power under acceleration.
It wants to die instead of accelerate.

What am I missing?

Could a new replacement coil go bad?
When I first replaced this coil the rpm range came back.

Side note...
I have a thought that maybe the timing chain might have skipped a tooth...

Does anyone know of a distributor shop that can rebush and restore factory points distributors?

[f.monroe]

Is it a fresh engine? If so was the cam broken in properly? A friend had some of the same issues and that's what it ended up being.
Frank
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[RPOZ11]

No Sir, It is the original 454 GM installed in my truck back in June of 1973.
Stock bore... 115,000 miles

[f.monroe]

I assume it's a single points distributor?what gap are the plugs set at and is there an inline resistor to reduce the voltage at the coil?

Frank
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[RPOZ11]

Single point breaker plate.
I have tossed around using my dual points breaker plate but have decided to save those for my Camaro distributor.

.035 on the spark plug gap.

As far as i know, regarding an inline resistor, I am only using the Factory brown wire supplied from the wiring harness to the positive side of the coil.

[f.monroe]

It's been a while since I worked on points but I think there should be about 7.5-8.5 volts at the coil. If it is full voltage it will burn it up. I may be wrong but if you are going through coils I would look into it.
Frank
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