Jetting should make a difference on even and odd cylinders, and not on one
bank or the other.
In reading this thread through all the posts I can tell you , you have two
carbs on there that are too big.
They are too big even if there was only one carb.
The R4 was a pretty specific high rpm design, and not really meant for
running around town and going to the store.
Maybe that would be ok if you were drag racing, but not so good for the
street.
By basic airflow standards applied generically to carbs, a 304 engine should
only need about a 650 cfm single carb.
You are running double that. Even with two 500cfm AFB carbs you are 400 cfm
too big.
Now you can get away with that under certain conditions and with certain
carb settings (delayed, or limited secondary throttle blade opening)
Both carbs should match (rod and jet wise) on the primary side, and they
should match (rod & jet wise) on the secondary side too.
The carbs should be synchronized as far as idle goes (that will be a trick
with a Uni-Syn as it is designed for a teeny 1bbl and 2bbl.
And making the distributor a manual advance only is a mistake.
Your initial timing may be ok, but the total will be not enough, or if you
set it for total advance, your initial would be too much.
You should hook up the vacuum advance back up.Hook it to whatever carb has
the correct port available.
Reading your plugs is the correct thing to do.
They are talking (no...yelling)  to you.
Your fuel distribution is way off.
Look at the manifold runners and then look at the carb sides you are
changing jets on.
Whatever you did on #8 to get that tan color is what you want to get on the
others.
With carbs that are too big, you run the problem of 'loss of signal' to the
carb.
The carb sees such low airflow that there is not enough vacuum at the
venturi to pull enough fuel in (OK, outside air pressure to push it into the
low pressure area in the venturi,,,,for you Bernoulli fans).. Then when you
step on the gas the butterflies open and there is a massive inrush of air,
without enough fuel to burn, and hence the huge bog off the line. The
accelerator pump shot of fuel is designed to get you past this (hopefully)
short transition period to where airflow has increased to the point where
the signal the carb sees at the venturis is enough to keep the engine
running strong.
But.... If the engine doesn't see enough signal, then the seemingly logical
thing to do is 'fatten' up the jets on the primary side.
This may help a little bit, but it won't cure the base problem, which is too
big a throttle bore for the displacement (airflow) the engine 'really' sees.
Glad you are keeping track of the numbers, because without a diary of jet
and rod changes and their effects on the engine, you can get way lost real
quick.
Reverting to 1964 OE spec's will get you back to a baseline, but that will
only get you back to your starting point.
You will still need to tweak 'your' engine to where it likes to be.
Your timing changes are the first thing I would go back to and retrace your
steps.
Hook the vacuum advance back up and reset your initial timing and then check
your total advance with a setback timing light.
Make sure these are 'close' to OEM specs.
Then go back to your baseline carb jet and rod spec's.
Triple check your throttle linkage to be extra sure the primaries are
opening when they should, and that the secondaries open later.
Check (ignition off) that the throttle butterflies are opening all the way
with a flashlight.
Check your fuel pressure at idle and at mid rpm.
Then run it with the stock rod and jet combo on some cleaned spark plugs and
read them.
That's where to start.
Then make your primary jet/rod changes...one step at a time...to BOTH carbs.
Read the plugs again.
Then, when you have the primary side looking good, plug wise, start with the
secondaries.
When you have the secondaries jetted so the transition from primaries to
secondaries doesn't stumble, and the high rpm doesn't break up.
Write down that set up numbers and circle it in red <g>.
Then the only changes you will be making will have to do with seasonal
temperature swings, altitude changes, and other mods you do to the engine.
(You don't have altitude problems at +12 feet above sea level, do you>
<lol>..

If all this doesn't work, give me a call. I have a good pair of matched
AFB's I'll bring down (with my Strip-Kit).
We'll get 'er straightened out...
Jeff

"Michael - Roseland FL" wrote...

you do know that the two center cylinders on one side of the engine and
the two outside cylinders on the other side run on the same side of the
carburetor? As in 1,4,6,7 use one side and 2,3,5,8 use the other side?

I worked on the R4 this evening.  I had a curled up section of the
intake gasket so I loosened all the bolts and corrected it.  The front
and rear bolts were not tight and that caused the intake gasket to curl
up.  After correcting the gasket and tightening it up the car runs
excellent and my popping noise from the exhaust is gone.  The intake
was evidently sucking air and that explains why jetting down was giving
me strange spark plug readings.  I think I am getting iot slowly but
surely.  Persistance pays off in these situations.