Please help rid me of "ping" Options

[Wyvern]

I am working on a 73 1.7

Valves adjusted to spec
Points set using dwell
Timing on the nose at 27' @ 3500 rpm (vac lines plugged)

She runs fairly well. had lots of ping on a up hill.
I could rev through it ... More ping as revs drop under load.

Today I put in fresh 91 octane and 16oz of seafoam, took a nice drive up a mountain.
Almost all the ping is gone.

Should I retard the timing just a bit ?
Or other suggestions / input much appreciated.

[veekry9]

An extreme technique,filling each cylinder with Berryman's™ carb cleaner in turn,to the top.
Using the 50/50 acetone/trans fluid mix,pre-soak the plugs and exhaust studs.
Remove the plugs,disconnect the bat,rotate the crank to tdc and fill the cylinder with the Berryman's.
Let that soak for 2 hrs,while you gently attempt to loosen the exhaust studs without damage.
The exhaust can now be repaired and or maintained to perfect condition.
Discovering the solvent leaking past the exhaust valve will determine the seat condition.
A poor seal will mean a poor guide,so,drain and strain the oil,pull the valve cover,inspect the valve guides.
Use a syringe to suck the solvent out of the cylinder,and swab them out with long Q-tips,the industrial kind.
Rinse again and reswab,do [not] lose any swabs downhole,roll the crank slightly and repeat until relatively gritless.
Repeat the process for each cylinder for carbon free chambers and valves.
Give each hole a spray of light oil and roll the crank 720 minimum.
Use a borescope to inspect the now clean cylinders,most have record functions,looking for scratched bores.
Gap your plugs,and give each thd a lick of high temp copper anti-seize.Roll the engine to #1 tdc.
Marking and labeling each new plug ht and distributor,remove and repair/maintain,replacing the points.
Check the distributor shaft and bushings for damage and wear,the plates move freely and the vacuum canister functions.
Lube the plates,springs and centrifugal weights with a light coat of lithium grease.
Inspect the cap for carbon tracks and burned anodes,rotor for the same.
Insert the dizzy and set statically,refill the oil and start,setting the advance with the light.
Use a spray carb cleaner a few times to blow the loose carbon out.
A decent assessment of the cylinders and valves can be had without disassembly.

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