Been awhile...refresher on timing please and thank you

[Pinchecharlie]

So I have a stock gen1 sbc with an aftermarket hei
It's new to me with no real details , anyway
I hooked up my light
And at idle turned the knob until the balancer and tab zeroed out and got a reading of 34°?
This is just with everything hooked up in running condition.
I thought it would be a really low number between 10-18.
Just wonder what iam doing because I've realized lately iam a ****y mechanic lol.
I should plug advance and put in 30-34 ° before 3k and whatch out for detonation ?
Must be doing something stupid because it wouldn't run like that and it runs pretty good?
If you would please enlighten me I would appreciate it. Thanks Charlie

[The Rocknrod]

Tech paper on that - https://www.google.com/url?sa=t&rct=...xPU93aRTBZtX-w

Major info on that - https://www.google.com/url?sa=t&rct=...7Hdvbo1hQaQdxQ
"...In order to measure this you must do two things. First, you must
disconnect your vacuum advance and plug the port at the carb.
Secondly, you need to be sure that your Mechanical Advance has not
yet begun to advance your timing. This might happen if you have very
light advance springs or your idle speed is too high...."

Timing 101 - http://67-72chevytrucks.com/vboard/s...d.php?t=274806

More info - http://67-72chevytrucks.com/vboard/s...d.php?t=689321

I used "search" block upper right hand corner: