In 2006 I tried using .060 Cometic MLS head gaskets to cure this same problem. It worked for me then. A few years later while trying to diagnose an oil burning issue, I found that I had some odd valve stem wear. I pulled the heads to replace the bad ones. The Cometics were thrown away. I didn't have the cash for new ones, so I went with some Fel Pro 1009s I had in my parts stash. Since then, the detonation has been sporadic. My notes show little, but I did write that the Cometics and Comp XE285 cam idled smoother and ran great without detonation. I even had one page where I wrote that I had the timing set to 35-36 degrees for max power but the 23 degree initial made the car hard to start.
I know that using thicker head gaskets flies in the face of some opinions here. Some think the detonation would get worse due to lost quench. Other members say that at my current .056 quench distance, the effects of quench are barely there.
I have been looking at different head gaskets over the last few years. Every so often I am tempted to try this again. Dodgem got me thinking about it again.

The Fel Pro 1009:
4.410 bore .039 compressed. 9.7 cc volume 10.7 to 1 in my 493.
Fel Pro 1105:
4.590 bore .051 compressed. 13.7 cc volume 10.36 to 1
Edelbrock:
4.450 bore .038 compressed. 9.9 cc volume 10.74 to 1
The most interesting one is THIS:
http://www.summitracing.com/parts/fog-900464520/overview/make/chrysler

The Flatout would lower my compression to 10.11 to one. Surely that would run on 91 octane.
I'm looking at all options still. Tomorrow I'll check fuel pressure AND run the 110 octane fuel.