Solutions for too much compression

Hey now.
So this is a short block that I purchased from the Mopar Performance catalog about 17 years ago. I think it was advertised as “9.5 to 1” compression ratio. I put a set of rebuilt 360 heads on it and yes, I took the time to measure the head volume and deck height and all, and unfortunately found that the actual cr was really something like 9.7 to 1 at least. I put it together along with a Mopar Performance cam ( not sure of which part number, but probably a mild street Performance option) and have been driving it off and on since. Now I am finally messing around with things and trying to get the thing more dialed in, I find that if I put any timing advance in the thing more than about 3 initial, 22 total, or so, I get pinging. I just got a compression tester and measured about 180 psi , which seems to verify that my cr is a little high.
What to do..?
Bigger cam to lower cylinder pressure?
Just set this retarded timing and run it?
Try to recurve my advance to adapt to the situation?

Additional info:

Timing mark was verified with a piston stop.

I have verified that the cam is not off, by measuring the rocker movement at overlap ( 360 crank degrees from TDC )
Am using an old school strobe timing light, not dial back.

Running 91 octane Premium gas.

Holley 750 vacuume secondary with “stock” jets and such.

Lastly...
The engine actually runs pretty damb good. If I advance the timing, it really likes it off the line, but then I do get some pinging. Especially on initial stomp, so I thought the vacuume advance had something to do with it... but even with it disconnected I still have pinging.