More distributor/advance questions

Alright, so I got it all started again today. I reset initial timing to around 18 degrees (it jumps around a lot, so I'm pretty sure I'm between 15 and 20 leaning towards the 20 side). It looked like it was full in between 2000 and 3000 RPMs (my tachometer stops at 2k, but my REVNNATOR blinks for 1000 RPM increments) and was around 35 degrees max (or so, I think), so the plate looks like it did its job within a few degrees assuming various tolerances and all of that. Then I hooked up the vacuum and, around 3 or 4k RPM got over 50 degrees, so I'm going to take a few degrees out of the vacuum canister.

I was able to get my ported vacuum down to around 1 or 2 in HG (probably the low end of my gauge) so that is good, and my idle is around 750 RPM. However, I am now getting no vacuum on the manifold side of the carburetor. This might not be an issue if I keep my vacuum advance hooked up to the ported side, but I still think the carburetor may not be built right (wait, that was a question from a different topic in the fuel section. I have too many questions! ).

So, then I get paranoid and have to ask what detonation/pinging sounds like? I have a book that describes it as a can of marbles, and I don't hear anything right now out of the ordinary in my motor, but I haven't driven it on the street yet and it could be I am missing it. Is it something obvious I will notice? In my garage, the motor sounds don't change as I run it up into 3000 RPM, but I'm worried I may be missing something.

I also should have worn ear plugs. It gets loud under that hood!