<VV> Trouble with idle back & PG question

[Padgett]

Spent another fruitless hour that wound up with extraction of my aunchient 
Heathkit  ignition analyzer from the Sun DT-680 it has been sitting on for 
the last decade.  Fired it up after resetting everything including drilling 
the orifice in the PCV tube out to 1/16 (book says 5/64" but 1/16 was all I 
could  do by spinning the drill in my fingers). Smoke at idle mostly 
disappeared but get puffs when revved.

Shot of the ignition scope with engine at idle (without flash so several 
ignition pulses showing a little scatter) is at
http://padgett.ws/files/analyzer.jpg

Hokay, Unisys says carbs are balanced at 800 and 1500 rpm.  Idle in N at 
800 rpm is stable and smooth. 1/2 turn richer idle mixture from rpm drop.

Put in drive and drops to about 500 rpm. Only stays there for a few seconds 
before misfiring begins (timing light stops flashing). A "loose timing 
chain" rattle occurs (detonation ?) and the engine stalls. Theremocouples 
on #2 and #5 plugs are reading 240F with 80F ambient.

So question: is a 300 rpm drop when PG is put in gear at 800 rpm normal ? 
If the rattle is detonation, why (8 degrees initial and pretty much all 93 
octane now) ?

Did have a couple of weeks when it would idle, then went downhill. Seems to 
be a history of doing that with this car. Suppose should pull carbs off 
again and check all passages (are 66 -024s with PE and 50 jets. Is going to 
52 jets advised while open ?)

Seemed to be very little sediment in gas tank when pulled the sender. Note: 
ran best with almost no gas in tank, ok with 1/2, most cranky after put 
another 6 gallons of 93 in this morning. Not enough of a sample to know if 
related but may be an indicator.

Note: is quite cold blooded even with chokes full closed & 70-80 degree 
start, as soon as pull-off does its thing will stall. Several cycles 
required before will stay running. Related ?

Things would be a lot simpler if had a good running 110/PG to compare 
settings & readouts but don't so need to perform a data dump and ask.

Thanks,

Padgett