High compression engine and pinging

[cppursell]

Hey,

I just put in my '67 C10 a small block 350, with a non-stock cam and small chambered 283 heads on it. According to my cousin (which this engine is his), it has an 11.2:1 compression ratio. Last night, we got it in and started, and today I drove it around with 87 fuel. It runs smooth and strong and accelerates fine, but if I push a little more on the throttle it starts pinging. Any more pedal and it would start pinging and knocking worse (BTW this is with a 600cfm Edelbrock performer carb). I played around with the timing and it seems to run decent on 17 advanced for now. I plan to experiment with higher octane fuel, and:

I'd love your input on how I should go about with using higher octanes for this experimental engine. I don't know what to do to get rid of the pinging in this higher compression motor. I appreciate your help!

Tidbits:
I'm in CA, so all I can get is 91 (as far as I know). I do not know about octane boosters. There's a local airport where I could possibly try aircraft fuel.