Stripes

Ignition timing has 4 components: initial, the rate of advance, total advance, vacuum advance.

Your initial is 6BTDC. Thats low enough. Your total is 32BTDC. Most say the range should be 32-36 depending on load, size, weight, gearing, etc.  Close enough.

What is your rate of ignition advance? At 3000 RPM, is all 32 degrees in? Is it all in at 1800 rpm? You need to test for pinging with the current set up with the vacuum advance disconnected. If it doesn't ping then, try hooking the vacuum can to a ported carb connection and see what it does. If it pings without the V advance connected, what heads and or compression ratio are you running? Some head combo show 10.75 to 1, too high for today's pump gas in most cars. 

Those vacuum cans have different rates of advance AND differing total advance. On my car I found the v advance coming in too soon and providing too much. Looks like your can is providing 18 degrees at full vacuum. Many feel 10 degrees is about right. Stay away from adjustable v advance cans, they typically only adjust the total advance and not the rate of advance.  It sounds like you need a new v advance can.

An HEI puts nearly double the amperage to the plugs than a point ignition. Pontiac increased the gap from .035 to .060 when the HEI was initially introduced. In the years after that, many moved back to a .045 gap feeling the .060 was excessive. It will not hurt it to run any of those gaps, so the best way to know is to test your application. I run a .045 gap in my 469 with a factory HEI, and it likes it.

Remember, the most common issue with HEI swaps is the points style distributor had a resistance wire powering it limiting voltage but primarily amperage to the point set. An HEI needs full voltage and plenty of current to operate at its peak.  So run no resistor or resistance wire and ensure you have at least a 12 gauge or larger wire supplying power. You have to verify that with the engine running.

How many cars got "buys" into the second round?